Derbyshire 8-1 (0.5 overs) v Somerset (Target 266 to win)
Dot, dot, four, four, OUT
Lively start. Two dots, followed by two Harry Came boundaries.
But then he edges to keeper Tom Banton - and Craig Overton has his first wicket.
Wayne Madsen is the new man in.
Post update
Derbyshire 4-0 v Somerset (Target 266 to win)
The Derbyshire reply is underway, with two dot balls from Craig Overton to Harry Came, followed by an opening boundary.
Somerset innings comes to an end
Somerset 266-5 (20 overs) v Derbyshire
Rex FeaturesCopyright: Rex Features
Derbyshire are finally put out of their misery as Somerset have run out of overs.
A new T20 Blast record score of 266-5 - at an average of more than two runs per ball.
And the 82 runs off Mattie McKiernan's four overs - -capped by 36 off the last of them - is a new world T20 record.
There's a few people needing to get their breath back here.
Let's not write Derbyshire off yet. Who knows what might happen next? But let's just say they are now long odds. Very long odds.
New Blast record for Somerset
Somerset 263-5 v Derbyshire
Second successive six for Benny Green - and Somerset break the T20 Blast record.
That beats the 261-2 posted by Birmingham Bears at Trent Bridge just 22 days ago.
WICKET - Lammonby b Hughes 31
Somserst 251-5 (19.2 overs) v Derbyshire
Tom Lammonby is bowled for 31 off nine balls! Six of them went to the boundary.
Benny Green comes in to hit his first ball for six.
Post update
Somerset 251-4 (19 overs) v Derbyshire
Somerset's highest score in T20.
The highest ever against Derbyshire in T20.
And Derbyshire put them in!!!
One over left. Alex Hughes has been handed the poisoned chalice.
Post update
Somerset 235-4 (18 overs) v Derbyshire
Another 24 come off that Ben Aitchison over as Derbyshire's bowlers buckle.
Tom Abell and Tom Lammonby are maintaining the mayhem - and Somerset are heading for the record books.
Post update
Anthony Gibson
BBC Radio Somerset
This crowd here at Taunton rose to South African Rossouw, who has made such a tremendous contribution to this T20 campaign for Somerset. And he acknowledged the applause.
All around the ground people stood and cheered as a new hero for Taunton made his way to the Andy Caddick Pavilion.
WICKET - Gregory c McKiernan b Scrimshaw 1
Somerset 209-4 (16.6 overs) v Derbyshire
Second wicket in the over for George Scrimshaw.
Just three runs off it.
Four overs, two for 16.
In a 200-plus total, an amazing effort. He will be looking to repeat that form when he returns here to Taunton with the England Lions next week.
WICKET - Rossouw c Hughes b Scrimshaw 93
Somerset 207-3 (16.2 overs) v Derbyshire
Finally Rilee Rossouw is gone as George Scrimshaw once again slows things up.
He has been different gravy tonight.
Post update
Somerset 206-2 (16 overs) v Derbyshire
Dave Fletcher
BBC Radio Derby Sport
We have another innings to go here, but we can pretty much start the car now.
I think you can safely say Yorkshire v Lancashire in the first game and Somerset and Hampshire in the second game next Saturday.
200 up for Somerset
Somerset 206-2 (16 overs) v Derbyshire
The 200 comes up and Rilee Rossouw moves nearer a century on 93.
Four overs left. The Bears record T20 Blast score of 261 is under threat,
George Scrimshaw comes back on for his last one.
Post update
Dave Fletcher
BBC Radio Derby Sport
This is an absolute disaster for Mattie McKiernan.
The 82 off of his four overs is comfortably the worst figures by a Derbyshire player in the T20 Blast.
36 off one over
Somerset 191-2 (15 overs) v Derbyshire
Rex FeaturesCopyright: Rex Features
Brutal from Rilee Rossouw as the powerful left-hander dumps poor Mattie McKiernan into the River Tone, with the second of five sixes in the over.
16 off the first three balls, followed by a misthrow, ruled as a no ball.
Then comes another six swept over square leg, followed by another two out of the ground. Pure carnage!
Post update
Mark Davis
Former Somerset seam bowler
I'm amazed Mattie McKiernan is back on, he had gone for 46 runs off three. It's a big call to have called him back on.
Post update
Somerset 155-1 (14 overs) v Derbyshire
16 off that over - and a wicket. But Somerset are still clearly heading for 200 here.
One more to come from George Scrimshaw though.
Post update
Dave Fletcher
BBC Radio Derby Sport
The comeback starts here...
The earlier drop cost 44 runs. That's not great.
Post update
Mark Davis
Former Somerset seam bowler
It's getting away from Derbyshire now. It really is.
Somerset are hitting fours and sixes at will and they are under serious pressure.
WICKET - Banton c Reece b Hughes 73
Somerset 151-2 (13.3 overs) v Derbyshire
Tom Banton hits Alex Hughes for successive sixes then holes out to Luis Reece looking for a third.
Live Reporting
Ged Scott
All times stated are UK
Post update
Derbyshire 9-1 (1 over) v Somerset (266-5)
Wayne Madsen starts with a single.
A long way to go.
Second over coming up now from Josh Davey.
WICKET - Came c Banton b Overton 8
Derbyshire 8-1 (0.5 overs) v Somerset (Target 266 to win)
Dot, dot, four, four, OUT
Lively start. Two dots, followed by two Harry Came boundaries.
But then he edges to keeper Tom Banton - and Craig Overton has his first wicket.
Wayne Madsen is the new man in.
Post update
Derbyshire 4-0 v Somerset (Target 266 to win)
The Derbyshire reply is underway, with two dot balls from Craig Overton to Harry Came, followed by an opening boundary.
Somerset innings comes to an end
Somerset 266-5 (20 overs) v Derbyshire
Derbyshire are finally put out of their misery as Somerset have run out of overs.
A new T20 Blast record score of 266-5 - at an average of more than two runs per ball.
And the 82 runs off Mattie McKiernan's four overs - -capped by 36 off the last of them - is a new world T20 record.
There's a few people needing to get their breath back here.
Let's not write Derbyshire off yet. Who knows what might happen next? But let's just say they are now long odds. Very long odds.
New Blast record for Somerset
Somerset 263-5 v Derbyshire
Second successive six for Benny Green - and Somerset break the T20 Blast record.
That beats the 261-2 posted by Birmingham Bears at Trent Bridge just 22 days ago.
WICKET - Lammonby b Hughes 31
Somserst 251-5 (19.2 overs) v Derbyshire
Tom Lammonby is bowled for 31 off nine balls! Six of them went to the boundary.
Benny Green comes in to hit his first ball for six.
Post update
Somerset 251-4 (19 overs) v Derbyshire
Somerset's highest score in T20.
The highest ever against Derbyshire in T20.
And Derbyshire put them in!!!
One over left. Alex Hughes has been handed the poisoned chalice.
Post update
Somerset 235-4 (18 overs) v Derbyshire
Another 24 come off that Ben Aitchison over as Derbyshire's bowlers buckle.
Tom Abell and Tom Lammonby are maintaining the mayhem - and Somerset are heading for the record books.
Post update
Anthony Gibson
BBC Radio Somerset
This crowd here at Taunton rose to South African Rossouw, who has made such a tremendous contribution to this T20 campaign for Somerset. And he acknowledged the applause.
All around the ground people stood and cheered as a new hero for Taunton made his way to the Andy Caddick Pavilion.
WICKET - Gregory c McKiernan b Scrimshaw 1
Somerset 209-4 (16.6 overs) v Derbyshire
Second wicket in the over for George Scrimshaw.
Just three runs off it.
Four overs, two for 16.
In a 200-plus total, an amazing effort. He will be looking to repeat that form when he returns here to Taunton with the England Lions next week.
WICKET - Rossouw c Hughes b Scrimshaw 93
Somerset 207-3 (16.2 overs) v Derbyshire
Finally Rilee Rossouw is gone as George Scrimshaw once again slows things up.
He has been different gravy tonight.
Post update
Somerset 206-2 (16 overs) v Derbyshire
Dave Fletcher
BBC Radio Derby Sport
We have another innings to go here, but we can pretty much start the car now.
I think you can safely say Yorkshire v Lancashire in the first game and Somerset and Hampshire in the second game next Saturday.
200 up for Somerset
Somerset 206-2 (16 overs) v Derbyshire
The 200 comes up and Rilee Rossouw moves nearer a century on 93.
Four overs left. The Bears record T20 Blast score of 261 is under threat,
George Scrimshaw comes back on for his last one.
Post update
Dave Fletcher
BBC Radio Derby Sport
This is an absolute disaster for Mattie McKiernan.
The 82 off of his four overs is comfortably the worst figures by a Derbyshire player in the T20 Blast.
36 off one over
Somerset 191-2 (15 overs) v Derbyshire
Brutal from Rilee Rossouw as the powerful left-hander dumps poor Mattie McKiernan into the River Tone, with the second of five sixes in the over.
16 off the first three balls, followed by a misthrow, ruled as a no ball.
Then comes another six swept over square leg, followed by another two out of the ground. Pure carnage!
Post update
Mark Davis
Former Somerset seam bowler
I'm amazed Mattie McKiernan is back on, he had gone for 46 runs off three. It's a big call to have called him back on.
Post update
Somerset 155-1 (14 overs) v Derbyshire
16 off that over - and a wicket. But Somerset are still clearly heading for 200 here.
One more to come from George Scrimshaw though.
Post update
Dave Fletcher
BBC Radio Derby Sport
The comeback starts here...
The earlier drop cost 44 runs. That's not great.
Post update
Mark Davis
Former Somerset seam bowler
It's getting away from Derbyshire now. It really is.
Somerset are hitting fours and sixes at will and they are under serious pressure.
WICKET - Banton c Reece b Hughes 73
Somerset 151-2 (13.3 overs) v Derbyshire
Tom Banton hits Alex Hughes for successive sixes then holes out to Luis Reece looking for a third.
A costly drop that has cost Derbyshire 44 runs.
Tom Abell is the next man in.