We'll be back with you tomorrow morning from 04:30 BST for third practice and qualifying.
And finally...
We'll be bringing an end to this broadcast shortly, but before we go, here's some of your F1/marriage puns.
Adrian Peckitt: With This Pit I Re-Tread, Whether on slicks or Full Wets
Shaun Bristow: I pronounce you Mansell and wife
Christopher Hill: You may now kiss the apex
Paul Bateman: Does any person here present know of any lawful brakepedalment why these two persons should not be joined in matrimony
Sterling efforts all round.
Hamilton happy after trouble-free session
"It was better than Malaysia - I got to do the whole session so I'm happy," Hamilton told BBC Radio 5 live's Jennie Gow.
"Generally the car was feeling good and it was nice to get the running and the preparations. Hopefully that will stand me in good stead.
"The Ferraris look like they were as quick as they were in Malaysia. But hopefully we're quicker."
AFPCopyright: AFP
Vote result
The people have spoken...
We asked you to vote on the most surprising of all the surprise race winners over the years - but is it a surprise who came up trumps?
Jenson Button was your pick, taking 37.8% of the vote for his amazing win at the Canadian GP in 2011. Olivier Panis was second and Pastor Maldonado third.
Time for Jenson to crack open another bottle of bubbly...
Getty ImagesCopyright: Getty Images
Hamilton wraps up practice double
So, it's as you might expect at the very top of the order with Lewis Hamilton fastest overall at the end of today's practice sessions.
His best time, set on the soft tyre, was a 1:37.219 - around four tenths faster than the Ferrari of Kimi Raikkonen.
Red Bull's Daniel Ricciardo takes third, a second down on Hamilton, with the second Ferrari of Sebastian Vettel in fourth. Nico Rosberg is 1.2secs down on team-mate Hamilton, although he did not seem to get a clean lap on the softer - and quicker - Pirelli tyre.
Race pace 1st glance: HAM 0.5secs-ish faster than VET on softs; RAI & ROS closely matched on mediums. N.B. Subject to change on analysis
PACopyright: PA
Memo to Kimi and Nico - it's not Sunday
Bit of needle on track there between the Ferrari of Kimi Raikkonen and Mercedes's Nico Rosberg.
The two were side by side through the first corner and then continued to battle through the next few turns before Rosberg got ahead.
Save something for Sunday lads.
Pun time
Just on that bride and groom entry of a few moments ago. 'In sixth gear and in health'. Hmmmm, we're not sure.
We've come up with:
Marryussia
Holy Matra-mony
With this Hungaroring I thee wed
If you can do better (hint: you can) then get in touch on #bbcf1
Low-speed shunt drama
Daniil Kvyat just had an odd moment. With some flames and smoke coming from his left-rear brake, he was on a slow lap back to the pits but still carrying enough speed to run off track at the end of the long back straight.
The Red Bull bounced through a gravel trap and was almost at a stop when it kissed the crash barrier.
A soft impact but enough to remove the front wing.
Post update
F1 on Twitter: IN SIXTH GEAR AND IN HEALTH: Further proof that #F1 fans are the best fans!
F1Copyright: F1
F1 journalist Ian Parkes on Twitter
Police have arrested a Chinese #F1 fan who ran across the track along the main straight at the Shanghai International Circuit
Red Bulls on track - and shifting
Daniel Ricciardo, having spent much of FP2 in the garage due what Red Bull called "set-up tweaks", has gone third quickest on a 1:38.311.
Your top three with just under half an hour remaining is: Hamilton, Raikkonen, Ricciardo.
Getty ImagesCopyright: Getty Images
Vote for your most surprising F1 race winner
We've been asking all morning for your choices for F1's surprise race winners. We've tried to give you a taste of some of the standout candidates but it's far from an exhaustive list.
Even so, we've knuckled down to give you a list of eight race winners to choose from in a vote to find the most surprising winner.
We've gone for: Peter Gethin (1971 Italian GP), Vittorio Brambilla (1975 Austrian GP), Gilles Villeneuve (1981 Spanish GP), Olivier Panis (1996 Monaco GP), Johnny Herbert (1999 European GP), Sebastian Vettel (2008 Italian GP), Jenson Button (2011 Canadian GP), Pastor Maldonado (2012 Spanish GP). Apologies if your favourite is not listed.
Harry Harribo Repton: What about Johnny Herbert and Stewart GPS first win at the nurburgring in 99!
Steve Lank: For me it has to be Olivier Panis at Monaco in 1996 in a Ligier. What a legend!
Getty ImagesCopyright: Getty Images
Hamilton quickest
Moments before Felipe Massa's accident the Mercedes of Lewis Hamilton had clawed its way back to the top of the timesheets.
On the soft tyre, the reigning champion posted a 1:37.219 - four tenths quicker than Ferrari's Kimi Raikkonen, who also set his time on the soft.
AFPCopyright: AFP
Green flag
The Williams has been cleared away and we're off again.
Accident no 2 for Massa
Felipe Massa is having a trying day in the Williams.
The Brazilian, who span in FP1, lost his car under braking for the hairpin at turn 14 and skewed left into the barriers, his tyres squealing in protest as he went.
The front wing of his car was taken off and he's off back to the paddock on the back of a scooter.
Red flag
The Iceman cometh
Kimi Raikkonen has been out on a set of the soft Pirelli tyre and set the quickest time of the day by some margin.
The Ferrari has posted a 1:37.662 - 1.4s faster than Hamilton's previous best, posted on the harder tyre.
Hamilton and Mercedes team-mate Nico Rosberg have gone out on the soft so a response should not be long in coming.
Getty ImagesCopyright: Getty Images
F1's surprise winners - Peter Gethin, 1971
Getty ImagesCopyright: Getty Images
Peter Gethin never completed a full season in F1 yet his is a name familiar to F1 fans the world over.
After earning a single championship point in his debut year with McLaren in 1970, Gethin arrived at the 1971 Italian Grand Prix at Monza with a best finish of eighth place under his belt that year. A win was not on the cards, especially after the Briton qualified in 11th, 1.48secs behind Chris Amon's Matra.
And yet.
After a race of high attrition, the battle for victory came down to five men - Ronnie Peterson, Francois Cevert, Mike Hailwood, Howden Ganley and Gethin. In a mad last-lap scramble, Gethin vaulted from fourth to first to take the chequered flag by 0.1secs from Peterson - the closest finish in F1 history.
Who was that guy?
Just to fill you in on a replay we saw a little while ago, a man dressed in rather anonymous attire was seen to run across the track from the main grandstand to the pit wall.
He got across the track just a few hundred yards ahead of a Force India and leapt over the pit wall.
We've not heard the last of this. Suspect the FIA will have something to say at the very least.
Rosberg closes gap on Hamilton
Nico Rosberg was half a second behind Lewis Hamilton in FP1 - an age in this here sport - but he's already got that gap down in FP2.
The German's 1:39.126 is a big improvement on his morning. He trails Hamilton by 0.068secs.
Everyone has gone out in this session bar the two Red Bulls of Daniel Ricciardo and Daniil Kvyat.
AFPCopyright: AFP
McLaren crack out the flow-vis
McLaren on Twitter: Splash of neon in the garage earlier as the team spray flow-vis on Fernando's car.
McLarenCopyright: McLaren
Vettel troubles the gravel
We've had a handful of cars pointing the wrong way today and Sebastian Vettel's Ferrari has just become the latest, the German doing a full 360, just catching the gravel, on the exit of turn three.
He carried on and radioed back to say the car was in good nick. Just overdoing it.
AFPCopyright: AFP
F1's surprise winners - Olivier Panis, 1996
This was a great story. The 1996 Monaco Grand Prix is rightly remembered as one of the best races of all time. A huge number of retirements, incidents and surprises, at the end of which Ligier's Olivier Panis had come from 14th on the grid to win.
A wet and wild race began with reigning world champion Michael Schumacher sliding into the barriers on lap one and did not look back from there - with just 11 cars running on lap 31 of a scheduled 78.
Getty ImagesCopyright: Getty Images
Damon Hill led and retired, as did Jean Alesi on lap 60, handing a lead to Panis that he would not relinquish.
But that was not the end of it. Jacques Villeneuve collided with backmarker Luca Badoer to reduce the field further, and when Eddie Irvine's unwise spin-turn on a blind corner took out Mika Salo and Mika Hakkinen, just four cars were running.
That became three when Heinz-Harald Frentzen peeled off on the penultimate lap, leaving Panis, David Coulthard and Johnny Herbert the only men running at the chequered flag.
Grosjean disturbs BBC writer
I've been sat on this picture of Romain Grosjean since around 2am UK time and only now do I feel ready to share it.
It's... intense. Apparently it shows his jet lag.
Anyhoo, it's pertinent because he's actually in the car in FP2, having given up his seat to Britain's Jolyon Palmer in opening practice.
Roman GrosjeanCopyright: Roman Grosjean
Green light
Second free practice is under way.
Manor Marussia's Roberto Mehri is your first man on track.
EPACopyright: EPA
Post update
McLaren on Twitter: Paella with the press. Fernando Alonso and Eric Boullier spotted sharing tapas with the Spanish media.
McLarenCopyright: McLaren
Get involved - #surprisewinners
David Hardwick: Hill and R. Schumacher Jordan 1-2 Spa 1998. Surprised anyone made it to the end of the GP. Last men standing and Alesi 3rd
Kev Ambrose: Jo Siffert British Grand Prix, Brands Hatch 1968 in Rob Walker's Lotus 49
"For Red Bull, it has been a sobering start to the season. The controversy over Renault's lack of performance drew attention away from the team's struggles with their car in Melbourne, to the extent that when team boss Christian Horner, in the midst of his diatribe about the quality of Renault's engines, gave a very unconvincing answer to a question about why the Toro Rossos were so close to their big-budget works team, he was allowed to get away with it without a follow-up.
Getty ImagesCopyright: Getty Images
"Malaysia, though, brought home some uncomfortable truths - Toro Rosso flat beat the senior team there. Daniil Kvyat, promoted to Red Bull from Toro Rosso for this season said this 'opened our eyes a little bit'. And it is now clear that the RB11 is far from the greatest Red Bull the team have ever produced.
"Among the changes for this weekend are a reversion to a different brand of brakes from the one experimented with in Malaysia. Kvyat's team-mate Daniel Ricciardo said: 'Obviously we're experimenting with a few things but for now we're going to go back to what we know, to get the basics right. So we've reverted back on quite a few things and even to stuff from last year, which we knew was more efficient. It's obviously older, but it doesn't mean it's not better.'"
Bravo Mercedes, bravo
Mercedes on Twitter: Was it something we said?! #SadSeat #CheerUp
"There were further signs of significant progress from McLaren in first practice. Fernando Alonso was seventh fastest after the first runs. He did not improve after that, but Jenson Button did, leapfrogging ahead of the Spaniard and ending up 13th.
"McLaren gained what Button estimated to be 1.5secs on Mercedes between Australia and Malaysia and, while not expecting that progress again, expect to make another significant step in China.
"Will they be able to mix it in the lower midfield, thanks to Honda learning on the engine - the team's biggest handicap - and further aerodynamic upgrades this weekend?"
AFPCopyright: AFP
F1's surprise winners - Vittorio Brambilla, 1975
Vittorio Brambilla would finish in the points just nine times in a seven-year F1 career, with only one of those finishes on the podium. The top step to be precise.
After picking up just one championship point in his first F1 season, burly Italian Brambilla retired from eight of the first 11 races of 1975 before improbably winning the 12th - the rain-hit Austrian GP at the Osterreichring.
Having qualified his March in eighth, Brambilla made a flying start to run third early on before passing future world champions Niki Lauda and James Hunt to lead. With the rain intensifying, race officials called a halt to the race after 29 of 54 laps.
Brambilla famously crashed into the barriers within moments of taking the chequered flag, but his place in the history books was assured.
Get involved - #surprisewinners
We've been asking for your picks for F1's surprise winners.
We've had loads of great suggestions and we'll be recapping some of them as we amble through the next couple of hours.
Any more to add, get in touch on Twitter (#surprisewinners) via Facebook or by visiting our Google+ page
"Mercedes were in a different league in the first practice session, and this second 90 minutes should give a good indication of whether that advantage is real or whether Ferrari are in the ballpark again.
"It was the race-simulation runs in the second half of P2 in Malaysia that first indicated how strong Ferrari were looking there - as Ferrari technical director James Allison said in Sepang, 'those Friday runs tend not to lie'.
"So after the headline lap times are set on the soft tyre, the 'race sims' will make interesting reading."
Daniel Riley: Gilles Villeneuve '81 Spanish GP, with four cars on the tail of his 'Cadillac' Ferrari?
Graham Wilson: Pastor Maldonado, Barcelona 2012. kept it on track for the entire race. shocker.
Ariel Hernandez: Vettel in Monza 08. He's won so many races afterwards that one tends to forget how much of a shock that Toro Rosso win was.
Team radio
Williams driver Felipe Massa: "Engine was not good on the timed lap."
Massa finished that session in 10th place, just one-thousandth of a second behind team-mate Valtteri Bottas but a full two seconds off Lewis Hamilton.
Getty ImagesCopyright: Getty Images
FP1 times
Suzi Perry
BBC F1 presenter
FP1 timings - Lewis Hamilton in another sphere!
Suzi PerryCopyright: Suzi Perry
Tip of the hat to Jolyon Palmer, who completed 25 laps in that session and finished just six tenths off the pace of regular Lotus driver Pastor Maldonado.
Mercedes looking ominous at end of first practice
Ok, that's clearly first blood to Mercedes after the opening 90 minutes of the Chinese Grand Prix weekend.
A late, late lap from Sebastian Vettel made a mockery of my 04:30 entry, although the Ferrari man is still a fairly whopping 1.1secs off the pace of Lewis Hamilton.
Nico Rosberg is second, half a second down on his team-mate.
Chequered flag
Merc setting down a marker
I don't want to alarm anyone, but Lewis Hamilton is currently one and a half seconds clear of the nearest non-Mercedes runner. Team-mate Nico Rosberg is a second clear of Sebastian Vettel in third.
Do the Silver Arrows have a point to to prove?
Getty ImagesCopyright: Getty Images
Get involved - #surprisewinners
Curly: Fisichella, Brazil 2003
Sean Kelly: A *real* surprise winner was Peter Gethin at Monza 1971. Never finished in the top five in any other race
Zigzag: John Watson, Long Beach GP 1983 from 22nd on the grid!
Getty ImagesCopyright: Getty Images
And the next one please...
Felipe Massa has clearly been wondering what's so interesting about the run-off areas of this track so decided to take a look for himself - adding a neat pirouette into the bargain.
Satisfied, the Williams man drives on...
Post update
F1 on twitter: SPEED TRAP: Felipe Massa has spoiled the Ferrari party...
F1Copyright: F1
So far so good for Manor Marussia
Ben Edwards
BBC F1 commentator
"The two Manor Marussias have completed nearly 30 laps between them, which is certainly a step in the right direction."
Lurid moment for Lewis
Lewis Hamilton is the latest driver to explore the limits of the circuit, his Mercedes getting loose through turn one and running wide.
The Briton remains quickest with just under 10 minutes of this session to go.
Meanwhile, at McLaren
Jennie Gow
BBC Radio 5 live pit-lane reporter
A little light drilling for Fernando Alonso
Jennie GowCopyright: Jennie Gow
Post update
Mercedes on Twitter: 20 mins to go and a little lull in the session. We're planning one more run before session end
The good doctor - part two
Getty ImagesCopyright: Getty Images
So... returning to Jonathan Palmer (I said he was interesting).
After ending his racing career with Tyrrell at the end of 1989, a spell as a test driver with McLaren followed before he had a season in British Touring Cars in 1991.
Around this time he became the BBC's pit lane reporter, graduating to the role of co-commentator alongside Murray Walker following James Hunt's untimely death in 1993.
After those scoundrels at ITV nabbed the UK F1 TV rights at the end of 1996, Palmer focused on his business interests, including the formation of the Formula Palmer Audi Championship for young drivers (his son would take this route) and MotorSport Vision, which owns several tracks including Brands Hatch.
Back bother for JB
Jennie Gow
BBC Radio 5 live pit-lane reporter
"Jenson Button has been struggling with a bad back - he's had to miss some of his marathon training."
Jake Nichol: Giancarlo Baghetti France 1961 on debut. Vittorio Brambilla Austria 1975. Olivier Panis Monaco 1996
Alen Šmit: Button epic win in Canadian GP back in 2011, many stops, be on back of grid, crashes twice (ALO & BUT) and won...
Hmmm, I think history records that Alonso had a bit of a dubious helping hand at Singapore '08, Charles...
Mercedes out front
We're coming up on an hour gone and it's all as you'd expect at the top. Mercedes's Lewis Hamilton leading by half a second from team-mate Nico Rosberg, with Kimi Raikkonen's Ferrari in third.
"Sebastian Vettel was coy on Ferrari's chances of beating Mercedes again this weekend, but team-mate Kimi Raikkonen, who has had bad luck affect his hopes in both races so far, was more optimistic.
"'We have been with the car in Jerez [testing], in Barcelona and the first two races,' said the Finn. 'The car is working well in all conditions and circuits, so I don't see any reason why it should be something else here. It might be a bit different because it is cold, but the layout is probably closer to Barcelona than any race so far, and conditions are pretty similar. We will go out in practice, see how it is and try to work things out if we are not happy. But I don't expect any surprises.'
"Raikkonen said that Mercedes only looked so quick in Melbourne because he and Vettel had been stuck behind slower traffic early in the race. 'I said after Australia that if we would have been behind them in the race then I don't see that they would pull away, at least not as far as people think,' he said."
EPACopyright: EPA
The good doctor
Getty ImagesCopyright: Getty Images
A little more background for you now on Lotus new boy Jolyon Palmer, whose old man (above) is an interesting character.
A qualified doctor, Jonathan Palmer combined his racing interests with his medical career before focusing on the track, enjoying his first taste of success in Formula Ford in the late 1970s.
He won the 1981 British Formula Three Championship and the 1983 European Formula Two title. After testing for Williams in 1982, he made his F1 debut for the team at the 1983 European GP at Brands Hatch.
He went on to drive for RAM, Zakspeed and Tyrrell but never really lived up to his early promise, with fourth place at the 1987 Australian GP his best result.
Post update
Mercedes on Twitter: A little research into alternative lines - or, indeed, circuits - from Nico Rosberg at Turn 6 on that lap. He rejoins unscathed!
Rosberg's detour
Jolyon Palmer is in good company at very least, because many of his more illustrious peers are having a few lurid moments.
Several drivers have missed their braking points as they probe the limits of the track, with 2012 Shanghai winner Nico Rosberg the latest to do so, locking up and running wide into turn six.
Get involved - #surprisewinners
It's fair to say Sebastian Vettel's win in Malaysia last time out surprised a lot of people, with Mercedes having been widely expected to win in a straight fight.
That got the BBC F1 chimps scratching our heads and doing some quick blackboard sketches, at the end of which we came up with this:
We want you to tell us your most memorable surprise winners in F1. Simple as that.
I'm going to kick you off with Olivier Panis at the 1996 Monaco Grand Prix, because, let's face it, nearly everyone will say that. But I'm all ears for any others you can think of...
Lotus on Twitter: Very thorough drive from Jolyon. We can confirm 'practicing doughnuts' is on the work sheet.
LotusCopyright: Lotus
Palmer off track
Jolyon Palmer is testing the limits of the Lotus and has had a small moment on the exit of turn eight, the Briton pushing too hard and spinning off the black stuff.
He quickly gathers it up and is back on his way.
Where's the drivers?
Toro Rosso on Twitter: Moooooorning!!! Helmets waiting... Just need our drivers now. #FP1 about to start here in Shanghai! Who's watching!?
Toro RossoCopyright: Toro Rosso
First time on the board
Nico Rosberg sets the first time of the weekend, a 1:41.052 the early marker in a Mercedes that has been liberally showering the circuit in sparks from its titanium skid plate in these first few laps.
Replay gold for the TV director.
Will weather swing advantage back to Merc?
We're expecting a largely dry few days in Shanghai although there is the chance of a bit of rain later on Sunday.
Forecasters currently expect all the track sessions to remain dry, with any showers most likely arriving after the race.
Crucially there will be much lower ambient and track temperatures compared with Sepang last time out. We're expecting figures around 16-20C, with track temps in the mid 30s C.
"Mercedes driver Lewis Hamilton seems pretty convinced he could have won in Malaysia had things not worked out the way they did.
"The world champion felt that he had he not missed much of Friday practice with an engine problem, he might have learned enough about tyre usage and set-up for Mercedes to have approached the race differently. And he is holding to his view that even in the circumstances they had, stopping under the safety car was a mistake, because it lost him the best part of 10 seconds to Sebastian Vettel that he never really got back.
"'It wasn't the best weekend for us,' Hamilton said. 'There were lots of things we could have done better.'
"He admitted, though, that 'it was true pace Ferrari had. We'll get a better understanding here. We are not stressed and I think we will be stronger this weekend.'"
EPACopyright: EPA
Green light
First practice for the Chinese Grand Prix is under way.
Palmer makes F1 race weekend debut
There's a new Brit on the block this weekend with Jolyon Palmer in the cockpit of the Lotus for first practice.
Palmer, 24, won last season's GP2 title to become the first Briton to do since Lewis Hamilton in 2006.
He is the son of former F1 driver and BBC commentator Jonathan Palmer, who made 82 grand prix starts between 1983 and 1989.
AFPCopyright: AFP
Chinese Grand Prix - all you need to know
Just ahead of the drivers hitting the track, a quick reminder of our facts and stats feature, which you can find here.
"The Chinese Grand Prix could be a seminal race in this 2015 Formula 1 season.
"After Mercedes crushed the field in the opener in Australia, Sebastian Vettel's victory in Malaysia two weeks ago came as a huge surprise.
"But was it a unique combination of circumstances that played into Ferrari's hands, or will they be able to challenge Mercedes all season?
"The much cooler conditions of Shanghai could provide something of an answer."
EPACopyright: EPA
Will history repeat?
Twelve months ago Mercedes enjoyed a one-two finish at the Chinese Grand Prix, with pole-sitter Lewis Hamilton winning ahead of Nico Rosberg, with Ferrari's Fernando Alonso third.
The two Mercedes drivers can expect to be on the podium again this weekend - and can expect a Ferrari to once again be snapping at their heels after Sebastian Vettel showed the Scuderia's pace with a fine win in Sepang last time out.
It should be fascinating to see how the Mercedes-Ferrari battle unfolds over the next few days.
A feast of sport
There's a whole lotta sport going on this weekend, with major events in the world of golf, football, rowing and horse racing.
But, as you're reading this, I suspect for many of you the main draw will be events in Shanghai.
Good morning
Good morning and welcome along to our live text commentary of first practice ahead of the Chinese Grand Prix.
Live Reporting
Jamie Strickland
All times stated are UK
Get involved
AFPCopyright: AFP 
Getty ImagesCopyright: Getty Images 
Formula1.comCopyright: Formula1.com 
PACopyright: PA 
F1Copyright: F1 
Getty ImagesCopyright: Getty Images 
Getty ImagesCopyright: Getty Images 
Getty ImagesCopyright: Getty Images 
AFPCopyright: AFP 
Getty ImagesCopyright: Getty Images 
Getty ImagesCopyright: Getty Images 
AFPCopyright: AFP 
McLarenCopyright: McLaren 
AFPCopyright: AFP 
Getty ImagesCopyright: Getty Images 
Roman GrosjeanCopyright: Roman Grosjean 
EPACopyright: EPA 
McLarenCopyright: McLaren 
Getty ImagesCopyright: Getty Images 
MercedesCopyright: Mercedes 
AFPCopyright: AFP 
ReutersCopyright: Reuters 
ReutersCopyright: Reuters 
Formula1.comCopyright: Formula1.com 
Getty ImagesCopyright: Getty Images 
Suzi PerryCopyright: Suzi Perry 
Getty ImagesCopyright: Getty Images 
Getty ImagesCopyright: Getty Images 
F1Copyright: F1 
Jennie GowCopyright: Jennie Gow 
Getty ImagesCopyright: Getty Images 
EPACopyright: EPA 
Formula1.comCopyright: Formula1.com 
EPACopyright: EPA 
Getty ImagesCopyright: Getty Images 
Getty ImagesCopyright: Getty Images 
LotusCopyright: Lotus 
Toro RossoCopyright: Toro Rosso 
BBCCopyright: BBC 
EPACopyright: EPA 
AFPCopyright: AFP 
BBCCopyright: BBC 
EPACopyright: EPA 
APCopyright: AP
Latest PostGoodbye all
That's it for today's live commentary. Thanks as ever for your company and interaction.
Andrew Benson's FP2 report is now on the site and can be read here. We'll also have an update on the track invader and any other juicy lines we can lay our hands on.
We'll be back with you tomorrow morning from 04:30 BST for third practice and qualifying.
And finally...
We'll be bringing an end to this broadcast shortly, but before we go, here's some of your F1/marriage puns.
Adrian Peckitt: With This Pit I Re-Tread, Whether on slicks or Full Wets
Shaun Bristow: I pronounce you Mansell and wife
Christopher Hill: You may now kiss the apex
Paul Bateman: Does any person here present know of any lawful brakepedalment why these two persons should not be joined in matrimony
Sterling efforts all round.
Hamilton happy after trouble-free session
"It was better than Malaysia - I got to do the whole session so I'm happy," Hamilton told BBC Radio 5 live's Jennie Gow.
"Generally the car was feeling good and it was nice to get the running and the preparations. Hopefully that will stand me in good stead.
"The Ferraris look like they were as quick as they were in Malaysia. But hopefully we're quicker."
Vote result
The people have spoken...
We asked you to vote on the most surprising of all the surprise race winners over the years - but is it a surprise who came up trumps?
Jenson Button was your pick, taking 37.8% of the vote for his amazing win at the Canadian GP in 2011. Olivier Panis was second and Pastor Maldonado third.
Time for Jenson to crack open another bottle of bubbly...
Hamilton wraps up practice double
So, it's as you might expect at the very top of the order with Lewis Hamilton fastest overall at the end of today's practice sessions.
His best time, set on the soft tyre, was a 1:37.219 - around four tenths faster than the Ferrari of Kimi Raikkonen.
Red Bull's Daniel Ricciardo takes third, a second down on Hamilton, with the second Ferrari of Sebastian Vettel in fourth. Nico Rosberg is 1.2secs down on team-mate Hamilton, although he did not seem to get a clean lap on the softer - and quicker - Pirelli tyre.
Chequered flag
Edge with Hamilton
Andrew Benson
Chief F1 writer
Race pace 1st glance: HAM 0.5secs-ish faster than VET on softs; RAI & ROS closely matched on mediums. N.B. Subject to change on analysis
Memo to Kimi and Nico - it's not Sunday
Bit of needle on track there between the Ferrari of Kimi Raikkonen and Mercedes's Nico Rosberg.
The two were side by side through the first corner and then continued to battle through the next few turns before Rosberg got ahead.
Save something for Sunday lads.
Pun time
Just on that bride and groom entry of a few moments ago. 'In sixth gear and in health'. Hmmmm, we're not sure.
We've come up with:
Marryussia
Holy Matra-mony
With this Hungaroring I thee wed
If you can do better (hint: you can) then get in touch on #bbcf1
Low-speed shunt drama
Daniil Kvyat just had an odd moment. With some flames and smoke coming from his left-rear brake, he was on a slow lap back to the pits but still carrying enough speed to run off track at the end of the long back straight.
The Red Bull bounced through a gravel trap and was almost at a stop when it kissed the crash barrier.
A soft impact but enough to remove the front wing.
Post update
F1 on Twitter: IN SIXTH GEAR AND IN HEALTH: Further proof that #F1 fans are the best fans!
F1 journalist Ian Parkes on Twitter
Police have arrested a Chinese #F1 fan who ran across the track along the main straight at the Shanghai International Circuit
Red Bulls on track - and shifting
Daniel Ricciardo, having spent much of FP2 in the garage due what Red Bull called "set-up tweaks", has gone third quickest on a 1:38.311.
Your top three with just under half an hour remaining is: Hamilton, Raikkonen, Ricciardo.
Vote for your most surprising F1 race winner
We've been asking all morning for your choices for F1's surprise race winners. We've tried to give you a taste of some of the standout candidates but it's far from an exhaustive list.
Even so, we've knuckled down to give you a list of eight race winners to choose from in a vote to find the most surprising winner.
We've gone for: Peter Gethin (1971 Italian GP), Vittorio Brambilla (1975 Austrian GP), Gilles Villeneuve (1981 Spanish GP), Olivier Panis (1996 Monaco GP), Johnny Herbert (1999 European GP), Sebastian Vettel (2008 Italian GP), Jenson Button (2011 Canadian GP), Pastor Maldonado (2012 Spanish GP). Apologies if your favourite is not listed.
The vote will close at the end of FP2
Full terms and conditions here
Get involved #surprisewinners
Harry Harribo Repton: What about Johnny Herbert and Stewart GPS first win at the nurburgring in 99!
Steve Lank: For me it has to be Olivier Panis at Monaco in 1996 in a Ligier. What a legend!
Hamilton quickest
Moments before Felipe Massa's accident the Mercedes of Lewis Hamilton had clawed its way back to the top of the timesheets.
On the soft tyre, the reigning champion posted a 1:37.219 - four tenths quicker than Ferrari's Kimi Raikkonen, who also set his time on the soft.
Green flag
The Williams has been cleared away and we're off again.
Accident no 2 for Massa
Felipe Massa is having a trying day in the Williams.
The Brazilian, who span in FP1, lost his car under braking for the hairpin at turn 14 and skewed left into the barriers, his tyres squealing in protest as he went.
The front wing of his car was taken off and he's off back to the paddock on the back of a scooter.
Red flag
The Iceman cometh
Kimi Raikkonen has been out on a set of the soft Pirelli tyre and set the quickest time of the day by some margin.
The Ferrari has posted a 1:37.662 - 1.4s faster than Hamilton's previous best, posted on the harder tyre.
Hamilton and Mercedes team-mate Nico Rosberg have gone out on the soft so a response should not be long in coming.
F1's surprise winners - Peter Gethin, 1971
Peter Gethin never completed a full season in F1 yet his is a name familiar to F1 fans the world over.
After earning a single championship point in his debut year with McLaren in 1970, Gethin arrived at the 1971 Italian Grand Prix at Monza with a best finish of eighth place under his belt that year. A win was not on the cards, especially after the Briton qualified in 11th, 1.48secs behind Chris Amon's Matra.
And yet.
After a race of high attrition, the battle for victory came down to five men - Ronnie Peterson, Francois Cevert, Mike Hailwood, Howden Ganley and Gethin. In a mad last-lap scramble, Gethin vaulted from fourth to first to take the chequered flag by 0.1secs from Peterson - the closest finish in F1 history.
Who was that guy?
Just to fill you in on a replay we saw a little while ago, a man dressed in rather anonymous attire was seen to run across the track from the main grandstand to the pit wall.
He got across the track just a few hundred yards ahead of a Force India and leapt over the pit wall.
We've not heard the last of this. Suspect the FIA will have something to say at the very least.
Rosberg closes gap on Hamilton
Nico Rosberg was half a second behind Lewis Hamilton in FP1 - an age in this here sport - but he's already got that gap down in FP2.
The German's 1:39.126 is a big improvement on his morning. He trails Hamilton by 0.068secs.
Everyone has gone out in this session bar the two Red Bulls of Daniel Ricciardo and Daniil Kvyat.
McLaren crack out the flow-vis
McLaren on Twitter: Splash of neon in the garage earlier as the team spray flow-vis on Fernando's car.
Vettel troubles the gravel
We've had a handful of cars pointing the wrong way today and Sebastian Vettel's Ferrari has just become the latest, the German doing a full 360, just catching the gravel, on the exit of turn three.
He carried on and radioed back to say the car was in good nick. Just overdoing it.
F1's surprise winners - Olivier Panis, 1996
This was a great story. The 1996 Monaco Grand Prix is rightly remembered as one of the best races of all time. A huge number of retirements, incidents and surprises, at the end of which Ligier's Olivier Panis had come from 14th on the grid to win.
A wet and wild race began with reigning world champion Michael Schumacher sliding into the barriers on lap one and did not look back from there - with just 11 cars running on lap 31 of a scheduled 78.
Damon Hill led and retired, as did Jean Alesi on lap 60, handing a lead to Panis that he would not relinquish.
But that was not the end of it. Jacques Villeneuve collided with backmarker Luca Badoer to reduce the field further, and when Eddie Irvine's unwise spin-turn on a blind corner took out Mika Salo and Mika Hakkinen, just four cars were running.
That became three when Heinz-Harald Frentzen peeled off on the penultimate lap, leaving Panis, David Coulthard and Johnny Herbert the only men running at the chequered flag.
Grosjean disturbs BBC writer
I've been sat on this picture of Romain Grosjean since around 2am UK time and only now do I feel ready to share it.
It's... intense. Apparently it shows his jet lag.
Anyhoo, it's pertinent because he's actually in the car in FP2, having given up his seat to Britain's Jolyon Palmer in opening practice.
Green light
Second free practice is under way.
Manor Marussia's Roberto Mehri is your first man on track.
Post update
McLaren on Twitter: Paella with the press. Fernando Alonso and Eric Boullier spotted sharing tapas with the Spanish media.
Get involved - #surprisewinners
David Hardwick: Hill and R. Schumacher Jordan 1-2 Spa 1998. Surprised anyone made it to the end of the GP. Last men standing and Alesi 3rd
Kev Ambrose: Jo Siffert British Grand Prix, Brands Hatch 1968 in Rob Walker's Lotus 49
Red Bull go back to basics
Andrew Benson
Chief F1 writer
"For Red Bull, it has been a sobering start to the season. The controversy over Renault's lack of performance drew attention away from the team's struggles with their car in Melbourne, to the extent that when team boss Christian Horner, in the midst of his diatribe about the quality of Renault's engines, gave a very unconvincing answer to a question about why the Toro Rossos were so close to their big-budget works team, he was allowed to get away with it without a follow-up.
"Malaysia, though, brought home some uncomfortable truths - Toro Rosso flat beat the senior team there. Daniil Kvyat, promoted to Red Bull from Toro Rosso for this season said this 'opened our eyes a little bit'. And it is now clear that the RB11 is far from the greatest Red Bull the team have ever produced.
"Among the changes for this weekend are a reversion to a different brand of brakes from the one experimented with in Malaysia. Kvyat's team-mate Daniel Ricciardo said: 'Obviously we're experimenting with a few things but for now we're going to go back to what we know, to get the basics right. So we've reverted back on quite a few things and even to stuff from last year, which we knew was more efficient. It's obviously older, but it doesn't mean it's not better.'"
Bravo Mercedes, bravo
Mercedes on Twitter: Was it something we said?! #SadSeat #CheerUp
McLaren looking up?
Andrew Benson
Chief F1 writer
"There were further signs of significant progress from McLaren in first practice. Fernando Alonso was seventh fastest after the first runs. He did not improve after that, but Jenson Button did, leapfrogging ahead of the Spaniard and ending up 13th.
"McLaren gained what Button estimated to be 1.5secs on Mercedes between Australia and Malaysia and, while not expecting that progress again, expect to make another significant step in China.
"Will they be able to mix it in the lower midfield, thanks to Honda learning on the engine - the team's biggest handicap - and further aerodynamic upgrades this weekend?"
F1's surprise winners - Vittorio Brambilla, 1975
Vittorio Brambilla would finish in the points just nine times in a seven-year F1 career, with only one of those finishes on the podium. The top step to be precise.
After picking up just one championship point in his first F1 season, burly Italian Brambilla retired from eight of the first 11 races of 1975 before improbably winning the 12th - the rain-hit Austrian GP at the Osterreichring.
Having qualified his March in eighth, Brambilla made a flying start to run third early on before passing future world champions Niki Lauda and James Hunt to lead. With the rain intensifying, race officials called a halt to the race after 29 of 54 laps.
Brambilla famously crashed into the barriers within moments of taking the chequered flag, but his place in the history books was assured.
Get involved - #surprisewinners
We've been asking for your picks for F1's surprise winners.
We've had loads of great suggestions and we'll be recapping some of them as we amble through the next couple of hours.
Any more to add, get in touch on Twitter (#surprisewinners) via Facebook or by visiting our Google+ page
Mercedes bare their teeth
Andrew Benson
Chief F1 writer
"Mercedes were in a different league in the first practice session, and this second 90 minutes should give a good indication of whether that advantage is real or whether Ferrari are in the ballpark again.
"It was the race-simulation runs in the second half of P2 in Malaysia that first indicated how strong Ferrari were looking there - as Ferrari technical director James Allison said in Sepang, 'those Friday runs tend not to lie'.
"So after the headline lap times are set on the soft tyre, the 'race sims' will make interesting reading."
Welcome back
Ready for some more of the motor cars?
Me too. Thirty minutes til they're back on track.
Bye for now
Right, that's us done for the time being. You can read Andrew Benson's FP1 report here.
We'll be back at 06:30 BST for the build up to second practice, which gets under way at 07:00.
In the meantime, keep your surprise winners coming in. We'll recap some of your suggestions when we're back with you.
Get in touch on Twitter (#surprisewinners) via Facebook or by visiting our Google+ page
Get involved - #surprisewinners
Daniel Riley: Gilles Villeneuve '81 Spanish GP, with four cars on the tail of his 'Cadillac' Ferrari?
Graham Wilson: Pastor Maldonado, Barcelona 2012. kept it on track for the entire race. shocker.
Ariel Hernandez: Vettel in Monza 08. He's won so many races afterwards that one tends to forget how much of a shock that Toro Rosso win was.
Team radio
Williams driver Felipe Massa: "Engine was not good on the timed lap."
Massa finished that session in 10th place, just one-thousandth of a second behind team-mate Valtteri Bottas but a full two seconds off Lewis Hamilton.
FP1 times
Suzi Perry
BBC F1 presenter
FP1 timings - Lewis Hamilton in another sphere!
Tip of the hat to Jolyon Palmer, who completed 25 laps in that session and finished just six tenths off the pace of regular Lotus driver Pastor Maldonado.
Mercedes looking ominous at end of first practice
Ok, that's clearly first blood to Mercedes after the opening 90 minutes of the Chinese Grand Prix weekend.
A late, late lap from Sebastian Vettel made a mockery of my 04:30 entry, although the Ferrari man is still a fairly whopping 1.1secs off the pace of Lewis Hamilton.
Nico Rosberg is second, half a second down on his team-mate.
Chequered flag
Merc setting down a marker
I don't want to alarm anyone, but Lewis Hamilton is currently one and a half seconds clear of the nearest non-Mercedes runner. Team-mate Nico Rosberg is a second clear of Sebastian Vettel in third.
Do the Silver Arrows have a point to to prove?
Get involved - #surprisewinners
Curly: Fisichella, Brazil 2003
Sean Kelly: A *real* surprise winner was Peter Gethin at Monza 1971. Never finished in the top five in any other race
Zigzag: John Watson, Long Beach GP 1983 from 22nd on the grid!
And the next one please...
Felipe Massa has clearly been wondering what's so interesting about the run-off areas of this track so decided to take a look for himself - adding a neat pirouette into the bargain.
Satisfied, the Williams man drives on...
Post update
F1 on twitter: SPEED TRAP: Felipe Massa has spoiled the Ferrari party...
So far so good for Manor Marussia
Ben Edwards
BBC F1 commentator
"The two Manor Marussias have completed nearly 30 laps between them, which is certainly a step in the right direction."
Lurid moment for Lewis
Lewis Hamilton is the latest driver to explore the limits of the circuit, his Mercedes getting loose through turn one and running wide.
The Briton remains quickest with just under 10 minutes of this session to go.
Meanwhile, at McLaren
Jennie Gow
BBC Radio 5 live pit-lane reporter
A little light drilling for Fernando Alonso
Post update
Mercedes on Twitter: 20 mins to go and a little lull in the session. We're planning one more run before session end
The good doctor - part two
So... returning to Jonathan Palmer (I said he was interesting).
After ending his racing career with Tyrrell at the end of 1989, a spell as a test driver with McLaren followed before he had a season in British Touring Cars in 1991.
Around this time he became the BBC's pit lane reporter, graduating to the role of co-commentator alongside Murray Walker following James Hunt's untimely death in 1993.
After those scoundrels at ITV nabbed the UK F1 TV rights at the end of 1996, Palmer focused on his business interests, including the formation of the Formula Palmer Audi Championship for young drivers (his son would take this route) and MotorSport Vision, which owns several tracks including Brands Hatch.
Back bother for JB
Jennie Gow
BBC Radio 5 live pit-lane reporter
"Jenson Button has been struggling with a bad back - he's had to miss some of his marathon training."
Get involved - #surprisewinners
Charles Ndlovu: Alonso 2008 Singapore win from p15.
Jake Nichol: Giancarlo Baghetti France 1961 on debut. Vittorio Brambilla Austria 1975. Olivier Panis Monaco 1996
Alen Šmit: Button epic win in Canadian GP back in 2011, many stops, be on back of grid, crashes twice (ALO & BUT) and won...
Hmmm, I think history records that Alonso had a bit of a dubious helping hand at Singapore '08, Charles...
Mercedes out front
We're coming up on an hour gone and it's all as you'd expect at the top. Mercedes's Lewis Hamilton leading by half a second from team-mate Nico Rosberg, with Kimi Raikkonen's Ferrari in third.
All 20 drivers have set a time.
Raikkonen expects strong Ferrari
Andrew Benson
Chief F1 writer
"Sebastian Vettel was coy on Ferrari's chances of beating Mercedes again this weekend, but team-mate Kimi Raikkonen, who has had bad luck affect his hopes in both races so far, was more optimistic.
"'We have been with the car in Jerez [testing], in Barcelona and the first two races,' said the Finn. 'The car is working well in all conditions and circuits, so I don't see any reason why it should be something else here. It might be a bit different because it is cold, but the layout is probably closer to Barcelona than any race so far, and conditions are pretty similar. We will go out in practice, see how it is and try to work things out if we are not happy. But I don't expect any surprises.'
"Raikkonen said that Mercedes only looked so quick in Melbourne because he and Vettel had been stuck behind slower traffic early in the race. 'I said after Australia that if we would have been behind them in the race then I don't see that they would pull away, at least not as far as people think,' he said."
The good doctor
A little more background for you now on Lotus new boy Jolyon Palmer, whose old man (above) is an interesting character.
A qualified doctor, Jonathan Palmer combined his racing interests with his medical career before focusing on the track, enjoying his first taste of success in Formula Ford in the late 1970s.
He won the 1981 British Formula Three Championship and the 1983 European Formula Two title. After testing for Williams in 1982, he made his F1 debut for the team at the 1983 European GP at Brands Hatch.
He went on to drive for RAM, Zakspeed and Tyrrell but never really lived up to his early promise, with fourth place at the 1987 Australian GP his best result.
Post update
Mercedes on Twitter: A little research into alternative lines - or, indeed, circuits - from Nico Rosberg at Turn 6 on that lap. He rejoins unscathed!
Rosberg's detour
Jolyon Palmer is in good company at very least, because many of his more illustrious peers are having a few lurid moments.
Several drivers have missed their braking points as they probe the limits of the track, with 2012 Shanghai winner Nico Rosberg the latest to do so, locking up and running wide into turn six.
Get involved - #surprisewinners
It's fair to say Sebastian Vettel's win in Malaysia last time out surprised a lot of people, with Mercedes having been widely expected to win in a straight fight.
That got the BBC F1 chimps scratching our heads and doing some quick blackboard sketches, at the end of which we came up with this:
We want you to tell us your most memorable surprise winners in F1. Simple as that.
I'm going to kick you off with Olivier Panis at the 1996 Monaco Grand Prix, because, let's face it, nearly everyone will say that. But I'm all ears for any others you can think of...
Get in touch on Twitter (#surprisewinners) via Facebook or by visiting our Google+ page
Palmer's little off
Ben Edwards
BBC F1 commentator
"That's where Pastor Maldonado went off last year whilst adjusting the switches on his steering wheel."
And here's the video of that mad moment.
Post update
Lotus on Twitter: Very thorough drive from Jolyon. We can confirm 'practicing doughnuts' is on the work sheet.
Palmer off track
Jolyon Palmer is testing the limits of the Lotus and has had a small moment on the exit of turn eight, the Briton pushing too hard and spinning off the black stuff.
He quickly gathers it up and is back on his way.
Where's the drivers?
Toro Rosso on Twitter: Moooooorning!!! Helmets waiting... Just need our drivers now. #FP1 about to start here in Shanghai! Who's watching!?
First time on the board
Nico Rosberg sets the first time of the weekend, a 1:41.052 the early marker in a Mercedes that has been liberally showering the circuit in sparks from its titanium skid plate in these first few laps.
Replay gold for the TV director.
Will weather swing advantage back to Merc?
We're expecting a largely dry few days in Shanghai although there is the chance of a bit of rain later on Sunday.
Forecasters currently expect all the track sessions to remain dry, with any showers most likely arriving after the race.
Crucially there will be much lower ambient and track temperatures compared with Sepang last time out. We're expecting figures around 16-20C, with track temps in the mid 30s C.
Watch the weekend forecast here.
'We are not stressed' - Hamilton
Andrew Benson
Chief F1 writer
"Mercedes driver Lewis Hamilton seems pretty convinced he could have won in Malaysia had things not worked out the way they did.
"The world champion felt that he had he not missed much of Friday practice with an engine problem, he might have learned enough about tyre usage and set-up for Mercedes to have approached the race differently. And he is holding to his view that even in the circumstances they had, stopping under the safety car was a mistake, because it lost him the best part of 10 seconds to Sebastian Vettel that he never really got back.
"'It wasn't the best weekend for us,' Hamilton said. 'There were lots of things we could have done better.'
"He admitted, though, that 'it was true pace Ferrari had. We'll get a better understanding here. We are not stressed and I think we will be stronger this weekend.'"
Green light
First practice for the Chinese Grand Prix is under way.
Palmer makes F1 race weekend debut
There's a new Brit on the block this weekend with Jolyon Palmer in the cockpit of the Lotus for first practice.
Palmer, 24, won last season's GP2 title to become the first Briton to do since Lewis Hamilton in 2006.
He is the son of former F1 driver and BBC commentator Jonathan Palmer, who made 82 grand prix starts between 1983 and 1989.
Chinese Grand Prix - all you need to know
Just ahead of the drivers hitting the track, a quick reminder of our facts and stats feature, which you can find here.
Are Ferrari genuine contenders?
Andrew Benson
Chief F1 writer
"The Chinese Grand Prix could be a seminal race in this 2015 Formula 1 season.
"After Mercedes crushed the field in the opener in Australia, Sebastian Vettel's victory in Malaysia two weeks ago came as a huge surprise.
"But was it a unique combination of circumstances that played into Ferrari's hands, or will they be able to challenge Mercedes all season?
"The much cooler conditions of Shanghai could provide something of an answer."
Will history repeat?
Twelve months ago Mercedes enjoyed a one-two finish at the Chinese Grand Prix, with pole-sitter Lewis Hamilton winning ahead of Nico Rosberg, with Ferrari's Fernando Alonso third.
The two Mercedes drivers can expect to be on the podium again this weekend - and can expect a Ferrari to once again be snapping at their heels after Sebastian Vettel showed the Scuderia's pace with a fine win in Sepang last time out.
It should be fascinating to see how the Mercedes-Ferrari battle unfolds over the next few days.
A feast of sport
There's a whole lotta sport going on this weekend, with major events in the world of golf, football, rowing and horse racing.
But, as you're reading this, I suspect for many of you the main draw will be events in Shanghai.
Good morning
Good morning and welcome along to our live text commentary of first practice ahead of the Chinese Grand Prix.