Essex's Harmer takes five wickets; Cook passes 50
Lancs' Buttler & Hameed out cheaply
Duckett scores 89-ball century
Stokes out for a duck for Durham
Fifties for Surrey's Roy, Burns & Sangakkara
Yorkshire v Surrey 316-4
Image source, Rex FeaturesSurrey's Kumar Sangakkara goes to his half-century.
And in other news, it's going to rain in Britain this week.
It's simply brilliant batting from the 39-year-old, who is approaching 1,000 Championship runs for the season at an average of more than 95.
He must qualify for England soon, no?
Essex 61-0 v Middlesex 246
It's approaching 8.15pm, but it's also 26 June.
The sun doesn't set for another hour at Chelmsford, so the floodlights aren't doing much!
Meanwhile, Alastair Cook is out of the nervous 30s - the Essex opener is 40 not out.
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Leicestershire have made a poor start to their reply against Northants' 261, losing openers Paul Horton and Arun Harinath to slip to 14-2.
Nottinghamshire are also responding having bowled Kent out for 180. They're finding it tough too and are 52-3. Even in-form Samit Patel has gone for just four runs.
Worcestershire are 102-3, with Joe Clarke (30 not out) and Brett D'Oliveira (34 not out) steadying the ship after early wickets were lost against Durham, who made 197.
Sussex are 324-6, with Chris Jordan (33 not out) and David Wiese (21 not out) adding valuable lower order runs against Gloucestershire.
Finally, Derbyshire are 192-7 against Glamorgan at Cardiff.
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Chris King: It's difficult. Mile away from Headingley, but putting kids to bed and need to work tonight. Would love to head down but such is
Warwickshire v Lancashire 244-8
He may have the most awkward batting style you'll ever see, but Shiv loves scoring runs.
The 42-year-old reaches three figures for the third time this season and 76th time in his career.
Throw away the coaching manuals, this fella knows what he's doing.
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Essex 47-0 v Middlesex 246
Image source, Rex FeaturesAlastair Cook's last four scores in the County Championship have been 39, 31, 31 and 36.
The Essex opener has just moved to 31 with his sixth boundary.
Couple of sixes Al, that will do!
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BBC Sport commentator Peter Miller says there hasn't been an uptick in attendance with day/night cricket at Cardiff, with fewer in the crowd for Glamorgan versus Derbyshire than was at the start of play.
Mixed reviews so far it seems and a lot of questions that come with the format. Share your thoughts using #bbccricket on Twitter.
B12Simon: Hoping the pink ball doesn't mean the best Test team for a day/nighter is the one day team.
Matt Niner: Genuinely think Day/Night games could save the longer forms of the game.
Image source, Rex Features
Warwickshire v Lancashire 233-8
That's three for Keith Barker since the tea break!
Stephen Parry is out lbw, big Keith has 3-47.
Shiv Chanderpaul may have to get a wriggle on - he's two away from his century.
Hampshire 172-7 v Somerset
Hampshire are collapsing quickly at the Ageas Bowl, Somerset are running riot.
Tim Groenewald nips one back in to Ian Holland and the stumps are splattered.
Hampshire have gone from 84-0 to 172-7.
Northants 261 v Leicestershire
Alex Winter
BBC Radio Northampton sport
A remarkable collapse has seen Northamptonshire bowled out for 261 having been 211 for 3. You can't say it's down to the pink ball at all really - the floodlights weren't on when the wickets were falling.
But it may work in their favour because now the floodlights are taking good effect under cloudy skies and they have a brand new pink ball to have a go at Leicestershire.
Nothing like an evening boost to the crowd here - if anything it's thinned out a little since the second interval. Perhaps got a touch chilly and I did mention those bus times.
Hampshire 172-6 v Somerset
This kind of sums up James Vince's season so far.
After easing his way to 47, he tickles a Jack Leach delivery down the leg side and Steven Davies clings on.
Vince still only has one century and not a lot else in 11 innings this campaign.
Yorkshire v Surrey 284-4
Image source, Getty ImagesJoe may be waiting a while to get a bat.
Surrey are beginning to turn the screw at Headingley, with Kumar Sangakkara approaching a half-century.
Of course he is.
Warwickshire v Lancashire 221-7
Well, well is this the game which turns around Warwickshire's season?
All four of their defeats have been by an innings, and their batting has been below par, so don't hold your breath Bears' fans.
But it's a super start to the final session.
Northants' innings has come to a close as Max Holden is pinned lbw by Leicestershire's Dieter Klein. He made 92. Considering they were 211-4 following Ben Duckett's rapid century, it seems a position wasted for the hosts.
Elsewhere in Division Two, Worcestershire are 68-3 in reply to Durham's 197. Pinch-hitters John Hastings and Joe Leach didn't come off, but Joe Clarke and Brett D'Oliveira are at the crease now.
Luke Wright has fallen for a wonderful 118 for Sussex against Gloucestershire. His side are 283-6 following his quick innings.
Nottinghamshire are 36-1, replying to Kent's 180 all out. They lost Jake Libby for 16, but Brendan Taylor and Steven Mullaney are batting now.
Derbyshire are 164-7 and struggling against Glamorgan at Cardiff, whose bowlers are piling on the pressure under the lights.
Warwickshire v Lancashire 219-7
And another! Two in four balls for big Keith Barker - Jordan Clark is pinned lbw for a duck.
Hmm, has batting suddenly become more difficult under the lights?
Shiv Chanderpaul is watching it all unfold from the non-striker's end - the veteran is 10 away from a century.
Warwickshire v Lancashire 219-6
Keith Barker has struck with just the second ball of the final session and it's last week's centurion Ryan McLaren.
The South African all-rounder edges one to wicketkeeper Tim Ambrose. This game continues to swing back and forth.
Hampshire 169-5 v Somerset
Sean Ervine goes, nicking Jack Leach behind.
Hampshire are wobbling after such a fine start.
And there's also been a wicket at Edgbaston...
Essex 18-0 v Middlesex 246
Image source, Rex FeaturesEssex are ticking along, relatively untroubled.
They're always untroubled while Alastair Cook is at the crease.
Although the former England Test captain has been out in the 30s in his last four Championship innings.
They'll want plenty more from the 32-year-old this time around.
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Looks like a decent crowd too James.
Glamorgan v Derbyshire 157-7
Nick Webb
BBC Wales Sport
The second session has belonged to Glamorgan's bowlers with the Derbyshire innings stalling in the twilight zone.
Wayne Madsen's 70 has been the innings of the day, but he fell to Timm van der Gugten early in the session.
Marchant de Lange ended Billy Godleman's long resistance on 34, as part of a superb spell which also accounted for Gary Wilson.
Two wickets for Graham Wagg and a third for van der Gugten saw Derbyshire struggle to 157-7 at the interval.