Somerset all out for 145 from final ball of their 20 overs in the final; Sean Dickson top scores with 53
Matt Henry and Ish Sodhi share seven wickets as Somerset bowl out Essex for 131 to win by 14 runs
Essex beat holders Hampshire by five wickets (DLS Method) in first semi-final
Joe Weatherley hits unbeaten 63 to help Hants post 170-7
Essex reach revised 12-over target of 115 after rain, with three balls to spare
Somerset beat Surrey by 24 runs in second semi-final
Surrey limit Somerset to 142-7 but dismissed for 118 in reply
Essex 102-5 (target 115 from 12 overs)
Liam Dawson might have raised some eyebrows but he's limited Essex to seven off the over.
Some great fielding in the deep from Aaron Beard denies Essex at least one run and potenailly three.
His first four deliveries go for five runs and then a fine yorker makes it a single off ball five and the last goes for a single too.
13 off the final over required for a place in the final for Essex.
Nathan Ellis will bowl it.
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I agree with Nick Moreland (14:16). They should decrease the wickets available as well as the runs.
Chris, Surrey
DLS is so unfair on the side batting first. Chasing team should (Essex) should have had an adjusted runs target in 12 overs, plus only 12/20 (or 6 in old money) wickets to use.
Brian from Hampshire (obvs!)
Glenn Maxwell
Australia all-rounder on BBC Radio 5 Sports Extra
Ellis, a bag of liquorice allsorts, has just about got it done. There was a bit of everything in that over!
Essex 95-5 (target 115 from 12 overs)
Slower ball from Nathan Ellis produces a dot ball to start while the second ball is top-edged away towards deep point where it drops safe between two fielders for a single for Sams.
Critchley clips a full-toss towards mid-wicket for a single off ball three.
Ellis produces a beautiful quicker delivery to bamboozle Sams for another dot. Is he wrestling back the initiative here?
Sams says no, he clubs the final ball, a slower one, just over the fielder's fingers at backward square for a maximum.
The last ball brings a WICKET. Ross Whiteley takes a fine catch high in the air just a yard inside the tope on the rope at backward point.
29 from 17 balls for Sams
The pendulum swings once more.
20 needed from 12 deliveries.
Liam Dawson gets the penultimate over.
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Nick Moreland: The DLS is not fit for T20 cricket.
Reckon Nick is a Hampshire supporter?
Essex 87-4 (target 115 from 12 overs)
Image source, Rex FeaturesThose two sixes were followed by a wide from John Turner, though he replies by drawing an 89mph swing and a miss from Daniel Sams.
Turner sends in another wide to the cheers of the Essex fans but James Vince fields nicely to limit the final ball to a single at mid-on.
Essex need 28 from 18 balls and look strong favourites with Sams and Critchley in the middle.
Ellis will bowl over 10, and presumably 12 too.
Another fine pick-up, powering the ball over deep mid-wicket with the aid of the breeze and Essex are in pole position.
He has 21 off eight balls.
In the slot from John Turner and over the rope at long-off from Matt Critchley.
Are both Essex batters warming up at the perfect time?
Glenn Maxwell
Australia all-rounder on BBC Radio 5 Sports Extra
Sams has got extreme power, he's an amazing athlete. He can do a great job with the bat, he has really worked on his power hitting.
Essex 70-4 (target 115 from 12 overs)
After a single from Matt Critchley, Daniel Sams hooks a short ball from James Fuller over the keeper's head for four, via an edge I suspect.
Back-to-back fours when John Turner allows a cut from Sams to squirm under him and to the rope.
Fuller sends down a wide from the third delivery and then Sams cracks him for six and though Fuller replies with two dots, the ask is under 12 an over.
45 needed from 24 balls.
He's a dangerous player and he's picked up James Fuller superbly to launch him into the stands over deep mid-wicket.
How Essex could do with a couple more of those to calm those nerves.
Image source, PA MediaEssex 54-4 (target 115 from 12 overs)
Three wickets and three runs from six deliveries have changed the complexion of this game, but Essex have plenty of batters capable of winning this almost single-handedly, not least skipper Simon Harmer.
John Turner finishes his over, which cost five and claimed a wicket. Good turn.
Five overs to go, Essex need 61 to win.
James Fuller back on to bowl.
Essex 50-4 (target 115 from 12 overs)
Ged Scott
BBC Sport at Edgbaston
Image source, Ged Scott - BBC SportEdgbaston now looks about three quarters full as the second semi-final crowd begin to arrive to merge in with the morning crew.
The floodlights are still on, but the sun is clearly out too, somewhere up above - and, among thr still threatening clouds, there is some serious blue sky breaking out over roughly in the direction of St Andrew's.
Fingers crossed it stays like this.
Essex 50-4 (target 115 from 12 overs)
Another.
Paul Walter is trapped infront by John Turner and despite a review, he has to go. Think he suspected an inside edge but nothing doing.
Hampshire are rampant.
Image source, Getty Images
Alex Hartley
Former England bowler on BBC radio 5 Sports Extra
Now Essex have two fresh batters at the crease, which is never ideal.
Hampshire are well and truly in the driving seat. Two wickets in an over in a rain-affected match swings the momentum so much.
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They need a better way of making a fair target in reduced games especially T20s. Always favours the team chasing with wickets in hand and teams batting deep.
Dan, Andover (hoping to be wrong)
Has anyone noticed that the T20 Blast games this year have been much lower scoring or is that just me?
Sam, Nottingham
Essex 43-3 (target 115 from 12 overs)
Seven off the over, but two wickets for James Fuller.
What an impact.
66 from 36 needed.
Hampshire sticking with seam for now.
Alex Hartley
Former England bowler on BBC Radio 5 Sports Extra
Good catch, the keeper turned to take it but Turner shouted 'mine' and it went straight into the mitts.
Essex 43-3 (target 115 from 12 overs)
Now then. They have got Dan Lawrence, he tries a bit swipe at a shorter one, maybe slower too, from James Fuller and edges high behind for Ben McDermott to take a good high catch.
Matt Critchley joins Paul Walter.
Essex 47-2 (target 115 from 12 overs)
Michael Pepper tries to launch James Fuller over his head but mistimes it back to third where John Turner just about holds on with his fingertips.
They'd have preffered Dan Lawrence but the Hawks will still be happy.
Tall Paul Walter is in. This pairing could be explosive.
Image source, Rex Features