David Bedingham makes 79-ball 100 for Durham against Worcestershire
Hampshire's Liam Dawson takes five-for against Warwickshire
Surrey reach 185-1 at the close against Kent, with Dom Sibley 87 not out
England's Harry Brook out first ball for Yorkshire at Lord's
Marcus Harris scores 214 for Leicestershire at Derby
Ricardo Vasconcelos hits unbeaten 166 for Northants v Glamorgan
Derbys v Leics 408-4
There it is - Marcus Harris pushes the ball back past spinner Alex Thomson and reaches 200 off 293 balls.
He's been out there for over six and a half hours but celebrates by lofting Thomson away over long-on for the first six of his innings.
Harris made his career-best 250 not out in a Sheffield Shield game back in 2018 - he looks capable of beating that here.
Somerset 284-7 v Notts 193
The new ball does more but it also comes off the bat even faster.
Certainly when it is Craig Overton's bat as he hits successive fours off Brett Hutton, one straight, one square on the offside and he is up to 24.
A very dangerous lusty hitter coming in at nine.
Essex 227-3 v Lancashire 146
The game has gone quiet since the dismissal of Dean Elgar.
Essex have added 21 with Tom Westley and Jordan Cox, but it has taken them more than 10 overs as Lancashire are bowling tightly for the first time in the innings.
Kent 244 all out v Surrey
All over for Kent as Jas Singh tries to swing Tom Lawes into the leg side and is adjudged lbw.
Hard to say at this stage what a par score might be but nightwatcher George Garrett showed it certainly is possible to stick around, batting for 130 minutes for his 48.
Lawes finishes with 3-53, while spinner Cameron Steel (3-34) takes his tally for the season so far to 17.
Somerset 274-7 v Notts 193
Cricket, a pint in hand, the view of the Quantocks in the distance.
It's no wonder that Taunton is a popular ground and there is a decent crowd in on this Saturday afternoon.
The locals are enjoying this as Craig Overton rocks back and pulls Luke Fletcher for four with that easy power he has.
Worcs 184 v Durham 244 & 47-2
Colin Ackermann doesn't do a lot more than dangle his bat and it costs him his wicket as Joe Leach has him caught behind.
David Bedingham is soon under way as he puts away a Leach no-ball though the covers for four - plus the two extras.
Hampshire 24-1 v Warwickshire 455
Charlotte Taylor
Southern Vipers spinner on BBC Radio Solent
Another somewhat failure for Ali Orr, he's not made too many impacts in the County Championship so far since his move from Sussex to Hampshire.
Just playing the wrong line.
The batters are getting themselves out, rather down to their mistakes rather than a brilliant bit of bowling.
That was a good bit of bowling though and Warwickshire needed that. They had a bit of a tail off at the end of their innings so to start well was important for them.
Somerset 266-7 v Notts 193
Three wickets needed to mop up this Somerset innings and Haseeb Hameed calls up for a new Dukes ball.
Luke Fletcher is handed first crack with it.
And the first ball pings off Tom Banton's bat as he flicks it out to midwicket for four.
Middx 246 v Yorks 159 & 13-2
Shan Masood is beaten for pace by one that skids off the pitch and the umpire says that's out.
Yorkshire in trouble and Joe Root comes to the crease having been dismissed for just five in the first innings.
Kent 239-9 v Surrey
Ben Foakes is airborne again and takes a superb leg-side catch in both hands as Joey Evison tries to swish away a ball from Tom Lawes but only gets an inside edge.
Kent need 11 for a batting point - a tall order, perhaps, against the reigning champions.
The Marcus Harris show continues at Derby. Leicestershire's Aussie opener is now 176 not out and they are 367-4, with Liam Trevaskis on 17.
After the early loss of Tom Haines, Sussex have made a solid start in reply to Gloucestershire's 417 all out. They are 76-1 with Tom Alsop 34 not out and Tom Clark on 26.
Ricardo Vasconcelos and Luke Procter have added 58 for Northants so far - they are 78-1 in the 25th over, having bowled out Glamorgan for 271.
Somerset 250-7 v Notts 193
Anthony Gibson
BBC Radio Somerset
Tom Banton strokes that away beautifully for his 50, moving off side, trots through for the single and there is a lot of happiness around the ground.
He's a very popular cricketer here, he's tried so hard to establish himself in Somerset's County Championship side and it's really good to see him get his ninth 50 for Somerset in first-class cricket.
Hampshire 16-1 v Warwickshire 455
Warwickshire can always rely on the big man!
Accurate and straight from OHD and he hits Hampshire opener Ali Orr in front of the stumps and that is out.
Good start for the Bears to back up their 455.
Kent 236-8 v Surrey
Cameron Steel drops fractionally short at Canterbury and Joey Evison hoists it over the boundary at mid-wicket.
The leg-spinner almost has his man next ball, but an inside edge to fine leg allows Evison to collect two more.
Worcs 184 v Durham 244 & 32-1
Durham have recovered well from the early loss of Alex Lees.
Colin Ackermann and Scott Borthwick have pushed the Durham lead up to 92.
Essex 218-3 v Lancashire 146
You can't bowl there to Tom Westley.
Twice in the over, George Balderson is too straight to Westley and the Essex captain strokes both balls for four.
One to deep square and the other to wide midwicket.
Somerset 250-7 v Notts 193
Four runs for Tom Banton brings up his half-century and 250 for Somerset.
His 50 came from 80 balls and included seven fours.
Craig Overton is his batting partner now.
Somerset 246-7 v Notts 193
This is getting interesting...
Lewis Gregory is pinned lbw second ball by Calvin Harrison and Notts have another!
The Somerset lead is 53 - they probably thought it might be a bit more than that at this stage.
The new ball is on the way as well.
Middx 246 v Yorks 159 & 5-1
Image source, Rex FeaturesThat is a very loose shot by Adam Lyth.
He wafts at an angled ball from Toby Roland-Jones and Josh de Caires takes a rolling, tumbling catch at first slip.
Kent 224-8 v Surrey
Lucky.
Jas Singh edges a good ball by Jordan Clark but it bisects first and second slip and runs away for four.
Surrey have had enough of Kent tail-enders today - they'll want to knock over these final two wickets in short order.