Ben Foakes hits unbeaten 112 for Division One leaders against Warwickshire
Liam Dawson makes hundred for Hampshire against Somerset
Second-placed Essex begin game against Middlesex on Monday
Durham - 40 pts clear in Division Two - bowl out Sussex for 266
Derbyshire all-rounder Anuj Dal takes five-for against Yorkshire
Leicestershire dismiss Gloucestershire for 159 at Grace Road
Worcs 72-3 v Glamorgan
A fairly even first session between these two promotion contenders, with Glamorgan picking up three early wickets after putting the hosts in.
Seamers Timm van der Gugten, Jamie McIlroy and James Harris have one each, but Gareth Roderick and Adam Hose have mounted a Worcestershire recovery with an unbroken partnership of 39 so far.
Durham v Sussex 100-0
Tom Clark and Tom Haines have ridden their luck somewhat but they've put on a fine century stand in the final over before lunch on the opening day.
Clark has 45 and Haines 47. Set fair for this afternoon at this rate.
Surrey 106-2 v Warwicks
Ed Barnard starts a new spell - as BBC WM Sport's Richard Wilford says he "wouldn't rule out" him opening the batting in this game in the absence of Rob Yates and Alex Davies because of his One-Day Cup form.
It's a good over, with just two singles added. Danny Briggs will continue from the other end.
Surrey 104-2 v Warwicks
Well, well - after his lengthy spell of self-denial, Dom Sibley has now cast aside his shell and is letting the bat flow.
A couple of steps down the pitch and he thumps Danny Briggs past mid-on for his third four of the morning and is now 30 not out.
Northants 79-3 v Lancashire
The skipper has gone.
Jack Blatherwick has got a lot of extra bounce from somewhere, it's spat up at Luke Procter and hit him on the glove, or possibly the splice, and squirmed across for Will Williams to take a smart catch in the slips.
Two big scalps in the 15 minutes before lunch and an encouraging session for Northants is unravelling quickly.
Rob Keogh is next man in, joining Sam Whiteman, who inside edges past his own stumps. Lancashire are well on top.
Surrey 100-2 v Warwicks
Dom Sibley punches a short one from Henry Brookes through the covers for four, then tucks the next round the corner and brings up the 100 for Surrey with a single to square leg.
Brookes is proving very expensive - 25 conceded from three overs so far.
Just a single for Yorkshire from the latest Derbyshire over at Scarborough. They are 88-1 after 26 with Finlay Bean 40 not out and skipper Shan Masood on eight.
Gloucestershire are having to work hard for their runs at Leicester and are currently 69-1. Chris Dent has 29 off 82 balls, with Ollie Price - so prolific in the One-Day Cup - on six.
Sussex 83-0 v Durham
Martin Emmerson
BBC Radio Newcastle
Durham went into this one with a 40-point lead at the top of Division Two, knowing a sizeable win, with other results going their way, could see them promoted this week and also end Sussex' hopes of promotion.
Incredibly the visitors have only won one game this season, their opener against Durham in April, and have drawn the other nine.
Sussex won the toss and chose to bat on a track which was used for the T20 game between England and New Zealand on Wednesday.
They are currently 83-0, but things could have been different if keeper Ollie Robinson had held a sharp chance earlier. Tom Clark was on 22 when he edged Bas De Leede behind but although the keeper got his left hand to it he couldn't hold on.
Clark now has 33. Tom Haines, who took 22 balls to get off the mark, is on 42.
Worcs 55-3 v Glamorgan
As you might expect on a Sunday morning, the bells of Worcester Cathedral are ringing out merrily. Perhaps it's also a mark of appreciation for that straight drive by Adam Hose, dispatching James Harris to the boundary.
It's Hose's third four and he's reached 16 not out, with Gareth Roderick on 28 as the Pears pair (so to speak) look to recover from the loss of those three wickets.
Surrey 93-2 v Warwicks
Henry Brookes overpitches and Jamie Smith is in far too good nick to miss out on that one.
The net delivery is less convincing as he carves down to third man, but it's another boundary.
Quote MessageIt's a joy to watch someone who strikes the ball this cleanly."
BBC WM Sport's Richard Wilford
Northants 77-2 v Lancashire
Oh no. This is a cruel way for a bright knock to end. A dreadful miscommunication from Emilio Gay and Sam Whiteman.
The ball was pulled away by Whiteman to the deep square boundary where Dane Vilas made a tumbling stop. Gay turned back expecting to run two but Vilas's fine throw from the short 47m boundary is sharp enough to run him out, Phil Salt breaking the stumps before Gay could recover.
He looks crestfallen. He has been in superb touch all morning. A 67-run partnership is broken not long before lunch.
Luke Procter joins Whiteman. Lancs have their tail up.
Surrey 77-2 v Warwicks
Henry Brookes starts with a wide and is then flicked down to fine leg for four as he errs in line to Jamie Smith.
The final ball of the over is short and wide and Jamie Smith cracks it away square to bring up a 50 partnership with Dom Sibley.
Smith has 36 not out from 34 balls.
Northants 74-1 v Lancashire
Didn't expect to use this icon before lunch on day one of a Championship game.
Jack Blatherwick comes on to bowl and his second delivery seems to slip out of his hand as he releases and zooms straight towards Sam Whiteman's right shoulder.
The Australian needs no invitation to swivel and hook the full-toss away for a towering six over deep backward square, narrowly avoiding an ice cream van.
Six runs and two for the no-ball. Productive for Northants.
Hampshire 66-2 v Somerset
James Vince has announced his entrance with a series of sweet cover drives, dispatching his first ball from Ben Green to the fence and meting out the same treatment to Jack Brooks.
The Hampshire captain is 12 not out alongside Nick Gubbins, who has 23.
Surrey 71-2 v Warwicks
Image source, Rex FeaturesAlmost 90 minutes into the opening session and Dom Sibley has the first boundary of his innings for Surrey.
It's a good one too as he clips OHD through-wicket with excellent timing. The England opener - should we call him 'former England opener' in these Bazball days? - adds a couple from the next ball and is 18 not out.
Surrey 65-2 v Warwicks
Spin at The Oval, where Danny Briggs has been introduced by Warwickshire. If Surrey's line-up, featuring five pace bowlers, was a reliable guide to conditions, you might perhaps be surprised to see a slow bowler in action on the opening morning.
Just a couple of singles added by the home side from the left-armer's second over.
Northants 62-1 v Lancashire
Slightly worried the G and Y keys on the keyboard are going to wear out today...
Emilio Gay brings up the 50 partnership with Sam Whiteman with a classic on-drive past the stumps at the other end, all the way to the rope.
His seventh four, all of which are worth watching, if you get the chance. He has 34.
No further joy for Leicestershire following the dismissal of Ben Charlesworth and Gloucestershire are 60-1 in the 20th over, with Chris Dent 25 not out.
Yorkshire, though, have just lost their first wicket at Scarborough with Adam Lyth lbw to Anuj Dal for 32 following an opening stand of 59 with Finlay Bean, who has 21.
Hampshire 50-2 v Somerset
Ben Green's first delivery was pumped down the ground for four by Toby Albert, but the Somerset medium-pacer strikes back later in the over by persuading Albert to drive into the hands of Sean Dickson at point.
Albert had just brought up the 50 partnership with Nick Gubbins, but his first County Championship innings for Hampshire is over now and skipper James Vince comes out to replace him.
Durham v Sussex 70-0
Presume there must be a rainbow over the Riverside as the sun is out but we have got Raine and Drissell on the field.
Ah, Ben Raine and George Drissell are bowling at opposite ends.
Mother Nature must be a Durham fan.
Sussex have scored four fours in 15 balls and Tom Haines is onto 39 from 55 balls.