Jay Miller:, external Murray has dropped a metaphorical piledriver on the second set.

Terry Mahoney:, external I watch it, he's losing. I stop watching it, he is 4-0 up in the second. I'm relying on you, please keep me informed.

Craig Wilson:, external Boarding flight shortly from Heathrow to Brussels. Hoping Andy Murray is in the final by the time I land.

Image source, Getty Images

Berdych is getting a beating. Should he just wave the white flag and conserve some energy for the next set? It won't be long until the Czech loses a set for the first time in this tournament and there's no sign of Berdych wanting to delay the inevitable as Murray skips to a 0-30 lead.

Berdych hauls himself back into contention though, levelling at 30-30. "Andy!" screams Andy as he butchers a simple-looking backhand. A messy game proceeds to deuce... splutters to advantage... coughs to deuce... both engines faltering... Murray with enough fuel in the tank to grab set point, though. And Berdych goes long, long, long. His fuel gauge is dangerously low. A second-set whitewash.

John Lloyd
1977 Australian Open runner-up on BBC Two

"It is going to be a really important next changeover for Berdych. He needs to reset, mentally, and get back into this match."

Andrew Steele, Southend: Not only was the first set magical but it took 76 minutes to win 7-6 which is the same order as their ranking. Spooky.

Image source, Reuters

Murray, like a fine puppeteer, pulling the strings, working his opponent this way and that before seeing him off with a driven forehand volley for 40-30. Berdych far less aggressive than he was in the first set, but that is perhaps Murray isn't allowing him to dictate as much. Murray arrows a thunderclap of a serve down the 'T' to conclude the game, and this is turning into a second-set romp. Who doesn't like second-set romps?

Aidan Williams:, external Murray has woken up. Beating Berdych badly in the second set. Real potential for a bagel. Come on Murray.

Bhavik Raja:, external Murray has clearly been pumped up by whatever Berdych said at the end of the first set. He's showing Berdych now!

John Lloyd
1977 Australian Open runner-up on BBC Two

"This set is just about over. Brilliantly constructed point from Andy Murray to win the double break. That variety of Murray, different heights, different spins, it is very frustrating to play against."

Piers Newbery
BBC Sport at Melbourne Park

"Unusual to see Berdych slip over twice within a few seconds on a hard court, but they can get a bit slick. They are given a once over between matches with what looks like old-school carpet cleaners, Melbourne's version of the much-loved foot/towel approach taken at the US Open."

Image source, AFP

Image source, Getty Images

Berdych seems to have lost some grip in his trainers as he slips at the net on his way to losing the first point, and is doing his best Bambi-on-ice impression on the baseline as he lets another point slip. The Czech studies his daps, but carries on. Berdych, regardless of the dodgy footwear, reins his opponent in to 30-30, but the big-serving Czech is not at his best. He falters at the net - an area where he was supreme in the first set - to gift Murray a break point. And the Scot is hurtling towards the end of this second set as a Berdych backhand drifts into the tape.

John Lloyd
1977 Australian Open runner-up on BBC Two

"Just because Berdych won the first set, it doesn't mean he is favourite to win the match. Best of three is much more of a sprint, whereas best of five is a marathon. There are so many ebbs and flows in a five set match.

"Murray has done tremendously well after the blow of losing the first set. Berdych, in the first eight games, had plenty of time dictating the pace, now he is rushing a bit and not constructing points as well. He's got to calm down a bit."

Image source, @HeatherWatson92

British women's number one Heather Watson:, external That moment when someone steals your KitKat chunky... #takeabreak #hestolemybreak #ausopen #staredown

A game which had it all, other than chokingly-tense drama and magical trick shots... other than that, it had an ace, a ballooned return from Berdych and super serve and volleying from Murray for a hold to love. Berdych's intensity has dipped and Murray's currently cruising.

The crowd oohing and ahhing at the players' brilliance. Berdych turning quickly on his heels to retrieve a lob... Murray patiently waiting at the net, whacks a driving forehand towards Berdych's forehand side... the Czech chases like an enthusiastic Labrador, but comes unstuck and fails to negotiate the barrier. Better from Murray in this set, a break point comes his way and he takes it! A clench of the fist from the Scot. He's in control.

Dane:, external Tight first set that one was tough to call! Be such played well and served well!

Tony Dhanda:, external This tennis match is hotting up nicely. I want to see more needle between the players!

An intriguing battle so far, with Tomas Berdych taking the first set.

But will it last? Who do you think is going to win this sem-final? You can vote on the right-hand side of this page, or via the vote tab on your mobile or tablet.

We'll shut the vote at the end of the second set and see what you reckon…

Image source, Reuters

Murray recovers from the first-set blow by collecting the opening two points with ease - a winning forehand into the corner, Berdych looping a forehand long... And the Scot then delves into his box of tricks - a fabulous crosscourt winner which has the crowd purring. Murray's 40-0 up and he's soon walking back towards his chair with a game in his back pocket, a dodgy Berdych return ending matters.

John Lloyd
1977 Australian Open runner-up on BBC Two

"That was a crucial set for both players but particularly Berdych. If he had lost that set after dominating at 5-3, the match could have slipped away from him. To hang in there and win that is psychologically huge."

Image source, AFP

Ugly from Murray. He slaps a forehand into the net and the set belongs to Berdych. The Czech has yet to drop a set in this tournament.

Ace! Berdych moves 7-6 ahead and now has set point. Murray to toss...

Cool from Berdych. He approaches the net and sets himself up for a sweet backhand volley. Level at 6-6. Berdych still serving...