Eight group matches across the country in the North and South groups
England bowler Ollie Robinson returns to action for Sussex against Gloucestershire
Ollie Pope scores unbeaten 52 for Surrey, Ben Stokes makes 20 for Durham
South Group: Surrey beat Middlesex by five wickets, Somerset beat Hampshire by seven runs, Kent beat Essex by 28 runs (DLS method), Gloucestershire beat Sussex by 27 runs
North Group: Derbyshire tie with Notts Outlaws, Leicestershire beat Yorkshire by 34 runs, Northants beat Lancashire by seven wickets, Worcestershire beat Durham by eight wickets
Middlesex 150-5 (17.3 overs) v Sussex
No repeat performance this evening on the century front from Middlesex's Stevie Eskinazi but he does make a valuable 64 for the visitors.
Gus Atkinson deceives him in the flight with a slower ball.
Eskinazi and Darly Mitchell (58) have helped steer this Middlesex innings after a sluggish start.
Northants v Lancashire 97-5
A welcome boundary by Danny Lamb ends a Brandon Glover over, but Lancashire only have four more to come to try and push on towards a defendable total. Lamb has nine and Steven Croft is 17 not out.
Gloucestershire 38-4 (7 overs) v Sussex
Oh dear!
Just when Gloucestershire were starting to pick themselves up after a poor opening, James Bracey is caught for one after a comfortable catch by Sussex's David Wiese off Tymal Mills.
Just a moment earlier, Chris Dent had been caught behind by a wicked delivery from left-armer Mills.
Durham 178-8 v Worcs 57-1
Brett D'Oliveira top edges over the keeper for six off Matty Potts, who concedes 16 from the sixth over of Worcestershire's run-chase. D'Oliveira is 26 not out and Jake Libby has 22.
Leics 170-2 v Yorkshire
Joe Root's latest over costs 15 and he has 1-33 from three as Leicestershire continue to build towards a daunting total.
Colin Ackermann lifts a full toss by Jordan Thompson over square leg for six at the start of the next and Arron Lilley ends it with a boundary.
Lilley is 78 not out, Ackermann has 32 and together they have so far added 71 in 5.4 overs since the demise of Scott Steel. There are four more to come and the Foxes are looking for a 200 + total.
Kent 89-1 v Essex
Image source, Rex FeaturesZak Crawley's eventful innings at the top of Kent's order comes to an end after a 26-ball 43.
He and Daniel Bell-Drummond (44 not out) have got the visitors off to a lightning start at Chelmsford.
Somerset 125-6 (15 overs) v Hampshire
Hampshire keep on making useful breakthroughs as Scott Currie claims the wickets of Tom Banton (77) and Lewis Gregory (1) in the same over.
Banton struck eight fours and five sixes in his 37-ball blitz for the hosts.
Northants v Lancashire 84-5
An important wicket for Northants as Ben Sanderson takes a sliding catch in the deep to send Dane Vilas on his way for 25. Graeme White is the successful bowler and he has 1-17 from three overs so far. Seven more to come in the Lancashire innings as Danny Lamb joins Steven Croft.
Leics 140-2 v Yorkshire
Leicestershire are motoring along at a rate of exactly 10 an over against Yorkshire Vikings. The latest sees Arron Lilley smash Matthew Waite over mid-off for six and he now has 59 from 34 balls.
Durham 178-8 v Worcs 31-1
He won't like that. Ben Stokes comes on for his opening over and Brett D'Oliveira clears the rope at long-on for six from his third delivery.
Stokes' final ball is put away for four by Jake Libby, but Durham have taken one wicket, with Riki Wessels mis-cueing a pull shot off Matty Potts in the second over of the innings.
Image source, Rex FeaturesNotts 34-1 v Derbyshire
A shaky start saw Notts' Alex Hales dismissed without scoring after being bowled by Derbyshire's Conor McKerr.
But the Outlaws are steadying the ship through Joe Clarke, who has raced to 24 runs in the opening quarter of an hour.
Kent 64-0 (5 overs) v Essex
Essex are being punished at Chelmsford for dropping Zak Crawley with a gift of a chance he presented off Jamie Porter.
Crawley (39 not out) and Daniel Bell-Drummond (24 not out) flaying the ball to all parts so far in this powerplay.
Gloucestershire 7-2 (2 overs) v Sussex
Image source, PA MediaA lightning start for Sussex at Hove and a poor one for the visitors as the returning Ollie Robinson's third ball is skied straight to Luke Wright by Gloucestershire's Miles Hammond.
Moments later, Ravi Bopara catches out Benny Howell as he runs out the all-rounder from cover as he tried to take a quick single.
Leics 118-2 v Yorkshire
Image source, Rex FeaturesArron Lilley slices Jordan Thompson for four and then tries to pull the next ball, which flies off the top edge and over the wicketkeeper's head for another boundary. It takes LIlley to a 28-ball fifty, his third in T20 cricket.
Northants v Lancashire 64-4
Lancashire lose two wickets in three balls at Wantage Road.
First, Alex Davies hits Brandon Glover to mid-off and goes for 23 and then Rob Jones is beaten by Tom Taylor's throw from fine leg as he tries to scamper back for a second run.
That's the half-way point of the innings and the Lightning have a lot of work to do.
Leics 99-2 v Yorkshire
Oh dear.
Scott Steel plays to backward point and partner Arron Lilley sets off for a single. Steel barely moves and Gary Ballance throws to the bowler's end where Dom Bess breaks the stumps. The Durham opener is run out for 32 by almost the length of the pitch.
His dismissal ends a second-wicket stand of 75 in eight overs. Colin Ackermann is the new batsman.
Duirham 178-8 v Worcs 4-0
We are under way again at New Road, with Worcestershire chasing a target of 179. Liam Trevaskis has the ball for Durham and it's good opening over, costing him only four singles.
Somerset 80-4 (9.3 overs) v Hampshire Hawks
Image source, Getty ImagesA well-compiled half-century from Tom Banton keeps Somerset ticking over at Taunton despite Hampshire taking wickets at useful intervals.
It's taken the England international just 22 balls and included four fours and four sixes.
Northants v Lancashire 54-2
They needed that. Dane Vilas Hoists spinner Graeme White over mid-wicket for six as the Lancashire total passes 50 in the eighth over at Wantage Road. Vilas is 12 not out and Alex Davies has 20.
Kent 11-0 (1 over) v Essex
The Battle of the Bridge is under way at Chelmsford with Kent batting first.
England batsman Zak Crawley finds the boundary in Sam Cook's first over to get the Spitfires rolling with Daniel Bell-Drummond at the other end.