Derbyshire's Shan Masood makes second successive double century
Somerset's Tom Abell scores career-best 150 not out against Surrey
Keith Barker takes 6-53 for Hants v Kent and James Vince hits a 99-ball hundred
Michael Burgess hits second successive hundred for Warwickshire
Josh Bohannon scores hundred for Lancashire against Gloucestershire
In D2, Worcestershire's Brett D'Oliveira makes 169 not out against Sussex
John Simpson hits 104 not out as Middlesex build big lead against Glamorgan
Ben Slater and Lyndon James score hundreds for Notts against Durham
McManus c Lyth b Revis 8 (Northants 181-8 v Yorks 296)
Another blow for Northants on the stroke of tea.
Lewis McManus, the wicketkeeper on loan from Hampshire, tries to steer Matt Revis to third man but only steers in into the hands of Adam Lyth at second slip.
There's some debate over whether the catch carried but Lyth was claiming it and the umpires see no reason to disagree.
Kent 305 v Hampshire 182-2
A moment of good fortune for James Vince in an otherwise sparkling exhibition as he collects four off the inside edge from a loose attempt at a cover drive.
He has 71 off 70 balls, Nick Gubbins has 61 off 92 and together they have so far added 125 for the third Hampshire wicket.
Leicestershire 213 v Derbyshire 280-2
Shan Masood has already passed 500 runs for the season in only his fourth innings and is now well on his way towards 600.
He runs Beuran Hendricks down to third man for an easy single to reach 150 off 205 balls.
Wayne Madsen is approaching 100 at the other end and they have now added 220 in tandem.
Briggs c A Cook b S Cook 6 (Warwickshire 251-7 v Essex 168)
Not bad for an oldie - Sir Alastair Cook dives to his right at first slip to snatch a good catch out of the air and give namesake Sam his second Warwickshire wicket of the afternoon.
Michael Burgess is still there on 65 not out and the champions lead by 83.
Surrey 83-3 v Somerset 337
Ollie Pope is again looking in good nick for Surrey as he and England team-mate Ben Foakes try to rebuild the Surrey innings.
Pope has 32 off 42 balls, with five fours, and Foakes is on 15 and the deficit is 254.
Gay c Brook b Bess 65 (Northants 164-7 v Yorks 296)
A nice partnership had developed between Emilio Gay and Luke Procter but it ends at 49.
Gay has overbalanced slightly trying to work Dom Bess to leg and flicked a catch via the pad to leg slip.
Big blow for Northants' as they try to limit this deficit.
Seven overs to tea at Wantage Road.
Image source, Getty ImagesGlamorgan 122 v Middlesex 336
Ffion Wynne
BBC Radio Wales
It's hard to believe that at one point, Glamorgan had reduced Middlesex to 110-6.
They have just been bowled out for 336, a lead of 214, with John Simpson finishing with a magnificent 104 not out.
He was well supported by a wonderfully entertaining 29 from Shaheen Shah Afridi - his highest first-class score.
The pitch is looking a lot flatter than yesterday - time for Marnus Labuschagne to step up for Glamorgan?
Kent 304 v Hampshire 156-2
In the over after James Vince reached 50, Nick Gubbins does likewise with a wristy flick for four off Matt Milnes.
He now has 11 fours, one more than his captain, but Vince levels up again by swinging Hamidullah Qadri away over mid-wicket.
Durham 230 v Nottinghamshire 240-3
Martin Emmerson
BBC Radio Newcastle
Image source, GettyBen Slater is keeping things together for Notts and in reaching the 10th first-class century of his career has edged them ahead of Durham as well.
It was a patient 100 and probably the most worrying moment of the innings was the moment he got there, when a cut shot off spinner George Drissell rebounded off the keeper's gloves and ran away for a single.
Durham's bowling attack looks blunt at the moment. They haven't taken a wicket since lunch on a flat and lifeless track.
Slater has also added 85 for the fourth wicket with Lyndon James, who has 45.
Lancs 154-2 v Glos 252
It was about this time yesterday that Gloucestershire were firmly pressing the self-destruct button.
They lost 6-31 to throw away a wonderful start.
You can't see Lancashire, far more battle-hardened in grinding out a score and dealing with adversity, making the same mistake.
Particularly with Steven Croft at the crease in his 193rd first-class match.
Josh Bohannon still goes well, on 73, but has edged Jared Warner just out of the reach of slip.
Glamorgan 122 v Middlesex 332-8
Middlesex have a real grip on this match as John Simpson turns Michael Hogan away for two runs and reaches a 237-ball hundred - the eighth of his first-class career.
The left-hander has added 60 for the ninth wicket with Shaheen Afridi, who is 29 not out, and the lead is now 210.
Kent 305 v Hampshire 145-2
Exhilarating batting by James Vince, who strokes Hamidullah Qadri away for his 10th four and then takes a single from the final ball of the over to reach 50 off just 48 balls. Few players are better to watch when they are timing it this well.
Lamb b S Cook 71 (Warwickshire 237-6 v Essex 168)
The new ball works for Essex as Matt Lamb plays down slightly the wrong line and is cleaned up by Sam Cook.
He hit 10 fours in his 140-ball innings and put on 113 with Michael Burgess, who has now been joined by Danny Briggs.
Kent 305 v Hampshire 135-2
It almost seems to be a case of 'anything you can do, I can do better' at the Spitfire Ground.
Nick Gubbins helps himself to two fours in the same Matt Milnes over and he is 42 not out, with James Vince on 43 - though Vince is still scoring at better than a run per ball.
Warwickshire 224-5 v Essex 168
Michael Burgess started the season with 178 against Surrey and he has followed that with a 95-ball fifty against Essex.
A single off Simon Harmer is also sufficient to raise a 100 partnership with Matt Lamb, who is now on 66 not out.
Warwickshire lead by 56, but the new ball will presumably now be taken.
You know how, if you spill salt, you're supposed to throw some over your shoulder to avoid bad luck.
Does the same apply if you drop a cricket helmet?
Image source, Rex FeaturesNorthants 140-6 v Yorks 296
An hour into the afternoon at Wantage Road and Northants are finding it tough to move the board along.
Even though wickets fell regularly throughout the morning, the scoring rate remained healthy.
But now Dom Bess and Steve Patterson have got a firm grip on proceedings as Northants try to edge back into the contest.
They remain a long way behind and hope that Emilio Gay can build on his half-century.
Image source, Getty ImagesKent 305 v Hampshire 117-2
Some days James Vince just makes it look so easy.
He collects three fours in the latest Jackson Bird over and has seven so far in his 34 off 31 balls.
Nick Gubbins is also looking good and has just driven Matt Milnes away for four to move on to 29. These two have now put on 60 in 11 overs.
Amla c C Overton b Brooks 15 9Surrey 48-3 v Somerset 337)
Image source, GettyJack Brooks is Somerset's first change and strikes in his second over as Hashim Amla seems to be caught in two minds.
He tries to lift the bat away, but the ball deflects off the face and Craig Overton takes a sharp catch at slip.
A big wicket for Somerset and Ben Foakes comes out to bat with Ollie Pope 12 not out at the other end.
Having totalled 491, Worcestershire have taken a wicket with the first ball of Sussex's reply, with Joe Leach bowling Ali Orr for a duck.
Nottinghamshire have their first batting point and Ben Slater and Lyndon James have a 50 partnership against Durham - the visitors are 205-3, with Slater now 89 not out.
The Middlesex total has reached 300-8 at Sophia Gardens, where John Simpson is now 83 not out and is batting in tandem with debutant Shaheen Afridi.
And, as we have just told you (see 2:20 entry), Derbyshire are going along with a spring in their step against Leicestershire, reaching 205-2, with Shan Masood 116 not out and Wayne Madsen on 55.