Any nerves Worcestershire supporters had at the start of this chase will have been settled by the visitors' steady start.

Captain Daryl Mitchell has just fallen for 13.

But the visitors need 113 from 15 overs. Should be a walk in the park.

Sussex are romping along at Hove as they bid to chase 205 to beat Hampshire.

Chris Nash and Luke Wright have both got off to fliers and have struck nine boundaries between them.

A win for Sussex and they're in the quarter-finals. Still a big ask from here though.

Welcome to Chelmsford, Mitchell. New Zealander seamer Mitchell McClenaghan drops his first ball short and Mark Pettini is waiting on the back foot to slap it over mid-wicket for six.

Jesse Ryder also gets in on the act against his fellow countryman, with a boundary to third man, a big six over square leg off the front foot and a drive through the covers for four more.

That's 21 off the over and together with three boundaries coming from Gurjit Sandu's opening over, represents an absolutely flying start for Essex.

Brendon McCullum strikes two successive sixes off Stephen Parry, the first almost in to the top-tier of the huge pavilion.

He rockets onto 41 not out off just 24 balls but loses partner Tom Lewis for a breezy 22 as Ashwell Prince holds a catch in the deep off Steven Croft.

The very next ball, McCullum's exhibition is over as he knicks off through to Alex Davies.

Could the Lightning pull off an upset now?

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Surrey on Twitter:, external Quite a view again from the commentary box @BBCLondonSport @NatWestT20Blast

This has been a decent fight from a young Yorkshire bowling attack.

Will Rhodes has been especially accurate, his two overs costing just nine runs as Northants struggle to find the boundary.

Glenn Maxwell has just been brought into the attack and although Alex Wakely smashes his second ball for four, the rest of the over costs just six runs.

Birmingham Bears number three Tom Lewis is clearly picking up some inspiration from his current batting partner Brendon McCullum.

The left-hander smashes a sweep shot off Arron Lilley all the way over the fence to keep the hosts on track.

Chris Nash isn't hanging around as Sussex start a mammoth chase of 205 at Hove against Hampshire.

He's tucked into Will Smith's opening over with two fours and a six to get the Sharks off and running.

At the end of the powerplay, Somerset 's chase is well behind the 57-0 Surrey had recorded at the same stage. Duckworth-Lewis says the par score for a successful chase at this point is 71-0.

Peter Trego is the latest man to go for 26 from 16 balls, caught by Kumar Sangakkara off the bowling of left-armer Sam Curran, while Jim Allenby was a victim of former England man Jade Dernbach.

BBC Newcastle's Martin Emmerson at Chester-le-Street:

"Two years ago Michael Lumb was on 96 in Chester-le-Street and set to become the first Notts player to score a T20 100. It was a faultless innings and then suddenly he was stumped.

"Tonight Rikki Wessels was nailed on to become that first centurion. I would have put my house on it. But on 97 he tried to paddle a ball from Usman Arshad and scooped it into the hands of the keeper. You had to feel for him.

"Either way it looks like Notts have kept their campaign alive though because I can't see Durham chasing down 199 to win. I would put my house on that!"

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Birmingham Bears have lost a wicket in the opening five overs of their pursuit of 146, but they've still got Brendon McCullum at the crease.

He may be a magician with a bat, but it looks like he's got himself in a spot of bother trying to play a ramp shot over his head off James Faulkner.

It's fair to say he missed making contact with the bat and the ball hit him in a sensitive area!

Middlesex will be disappointed with that, despite Neil Dexter guiding Graham Napier's final ball for a boundary in the third man area to finish on 18 not out.

The feeling is that their total is a little below par, with the innings stagnating after an early flurry of boundaries.

The visitors' case was not helped by the dismissal of Eoin Morgan for 29 in the penultimate over. The England one-day captain tried to swot away a ball from Shaun Tait angled down the legside but only found the gloves of wicket-keeper James Foster.

A very good first over from Liam Plunkett is followed up by a second, not-so-good one. It flies away for 25 runs as Yorkshire struggle to get some control over Northants.

Richard Levi, another international player who has had a quiet season, struck Plunkett for three boundaries and a huge six to get Northants' chase up and running.

Plunkett has had the last laugh however as he runs Levi out for 30 from 14 balls, before Josh Cobb is dismissed for a golden duck. Good fight back from Yorkshire.

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Nottinghamshire set 199 Durham to win in this huge North Group fixture, with Australia all-rounder Dan Christian making a potentially vital 14 from six deliveries.

Riki Wessels was the star of the innings though, his 97 the highest ever score by a Notts batsman in domestic T20 cricket.

Hampshire have set Sussex a huge target at Hove.

They've gone past 200 as captain James Vince finishes unbeaten on 90.

That's the third time he's carried his bat through an innings in the competition - and that's just this season!

Worcestershire will be chasing 150 for a place in the quarter-finals.

Derbyshire launched a slight recovery from 69-4, but no batsman could make a sizeable score once they got going.

Where's your money for this one?

Michael Hogan bowls the final over and Calum Haggett somehow manages to squeeze the ball to the boundary, before getting Stevens back on strike.

Darren Stevens slams a huge six into the temporary stand - that flew miles - but he falls the very next ball as he tries to win it with a six and scoops it to Chris Cooke.

Kent needed three runs from the last ball to win but Haggett was run out coming back for the second to give Glamorgan a win by one run.

That's a remarkable victory for Glamorgan, who needed that to boost their quarter-final chances. Some superb death bowling from Michael Hogan and Graham Wagg.

Brendon McCullum looked like he was giving himself a few sighters against Lancashire, but have no fear, he's back to his usual self.

The New Zealand captain cracks four, four, six, a dot ball and then another six off consecutive balls from Jordan Clark.

All of a sudden, he's raced to 22 not out off 11 balls.

Riki Wessels misses out on a maiden century in T20 cricket, as he loops an easy catch to Durham wicketkeeper Phil Mustard off the bowling of Usman Arshad.

Arshad picks up another crucial wicket with the very next ball, as James Taylor is caught at deep square leg for 37 from 22 deliveries.

Just when you thought it couldn't get any worse for Somerset. Johann Myburgh is run out second ball.

Peter Trego has come in swinging and hit three boundaries already, but it's a big uphill struggle from here.