Yorkshire's Joe Root and Harry Brook out for 44 and seven against Surrey
James Rew marks his call-up to the England Test squad with 86 for Somerset against Sussex
Ben Kellaway scores 139 for Glamorgan against Warwickshire
Teenager Ben Dawkins hits unbeaten 181 in Kent's game with Durham
Derbyshire's Ben Aitchison takes 5-47 as Middlesex are all out for 177 at Lord's
Ben Sanderson claims 5-47 as Northants dismiss Gloucestershire for 154
Gloucs 152-8 v Northants
Ollie Price faces Ben Sanderson on 49...
Full, wide - driven and missed! Over bowled.
Earlier in the over Matt Taylor steered Sanderson wide of the slips and to deep third for four to bring up the innings 150 in the 49th over.
it's getting a little darker here. 30 overs left feels optimistic.
Kent 348-1 v Durham
The new ball is taken by Durham and Ben Raine's first two deliveries disappear for four.
The first is an ungainly one-handed effort by Sam Northeast through the covers, the second is clipped down the ground and runs away to mid-on via the toe end of Raine's boot.
Big statement innings from Ben Kellaway today after being overlooked for the lions squad
Gareth, Cardff
Came c Duke b Higgins 15 (Middx 177 v Derbys 37-1)
Middlesex needed that.
The ever reliable Ryan Higgins makes the breakthrough as Harry Came is caught behind.
Matthew Montgomery is in at number three.
Lancs v Worcs 260-9
With just one first-innings wicket left to take, James Anderson has decided to take the new ball immediately, and the Lancashire captain comes back into the attack to try and polish off Worcestershire.
It's not quite the immediate impact that Anderson is looking for though as Matthew Waite hoicks him away for back-to-back boundaries.
Essex v Leics 280-6
Ben Green crashes a wide ball from Wiaan Mulder through the covers for four.
Matt Critchley will bowl the next over and Stevie Eskinazi pulls a 'half-tracker' over mid-wicket for a big six. Exactly what that ball deserved.
Eskinazi is 39 not out and Green has 15.
Somerset 293-4 v Sussex
Another tidy over from James Coles with just the one run coming from it.
Tom Abell is hurried by a short ball from Ollie Robinson, but plays with enough control to nudge the ball safely wide of the two slips to deep third for four.
Middx 177 v Derbys 37-0
So far, so good for Derbyshire as Luis Reece tries to drive a ball from Eathan Bosch and collects four runs from a thick edge down to third man in the 11th over of their innings.
Gloucs 139-8 v Northants
Ollie Price is on 47 and blocks Ben Sanderson into the covers.
He tries to get a single to leg to keep the strike but doesn't get the ball away this time.
Matt Taylor to face Luke Procter. The second ball is hit up in the air but safely behind square leg for one.
Yorkshire 275-4 v Surrey
Image source, SWpix.comA beautiful late cut from Adam Lyth towards the vacant off side boundary sees him move onto 99 not out and his partnership with Jonny Bairstow is now worth more than 150.
Two balls later, Lyth claims his 41st first-class century with a couple into the leg side - his first of the season.
A superb innings from the dependable left-handed opener.
Somerset 287-4 v Sussex
Interesting. Spinner James Coles has taken the new ball and nearly foxes Tom Abell with one that keeps a bit low.
15 overs left in the day's play - and Ollie Robinson takes the new ball at the other end.
He immediately gets bounce and movement but wide enough for Archie Vaughan to leave the ball.
Robinson adjusts his line and length. Vaughan plays and misses.
Maiden over.
The Blaze remain top of the group table following a three-wicket win over Hampshire at Trent Bridge.
Set a target of 210, they reached 211-7 off the first ball of the 46th over, with Emma Jones making an unbeaten 37 off 30 balls.
Lancs v Worcs 250-9
Worcestershire manage to get their first batting point in their final-wicket stand as Matthew Waite picks up a single to move onto 57 not out.
Glamorgan 253-4 v Warwickshire
Ben Kellaway (122*) has not rested on his laurels having reached three figures.
He has just taken Nathan Gilchrist for three boundaries in the space of five deliveries. The current partnership is worth 40 and Glamorgan have secured their first batting bonus point of the day.
Gloucs 136-8 v Northants
Ben Sanderson wasn't too far away from his fifth wicket as Matt Taylor pushes forward loosely and is beaten outside off stump.
The third ball of the over is fuller, wider and driven through cover for four.
Taylor gets another single to cover and now Ollie Price will face on 46.
An absolute beauty from Sanderson that swings in, beats the bat and goes through to the keeper.
A flashing drive and a miss to end the over.
Who said this game was easy?
Yorkshire 265-4 v Surrey
Jonny Bairstow has not made a century in the County Championsip for Yorkshire since he was made red-ball captain last year.
He may not get a better chance than today - he is currently 76 not out and batting as well as he has in a long time.
Partnered by Adam Lyth, who is now just six runs short of a century, and Yorkshire are currently in a very strong position.
Kent 319-1 v Durham
Image source, Getty ImagesClearly not daunted by reputations, Ben Dawkins swivels and pulls Ben Stokes for four.
Stokes bangs the next one into the unresponsive deck and Dawkins has plenty of time to thump this one away past mid-wicket and bring up his 150 from 233 balls.
Kent v Durham 311-1
You can never accuse Ben Stokes of being unwilling to put in the hard yards. The England skipper returns for another spell and Sam Northeast pulls down to long leg for a couple.
The next one brings Northeast three to mid-wicket and that is the 250 partnership. He has 114.
Somerset 282-4 v Sussex
James Coles to Tom Abell... outside off stump and played out to deep point for a single to reach 50.
93 balls with five fours and a six.
He's a run machine. That's the sixth time he's reached 50 in 10 innings this season. He also has two centuries.
Glamorgan 239-4 v Warwickshire
Glamorgan are placing the foundations for what they hope will be another strong partnership, with Sean Dickson on 14 alongside Ben Kellaway, who is still there on an unbeaten 109.
Dickson, Warwickshire fans will remember, took the T20 Blast quarter final away from them at Taunton last year while playing for Somerset.