Another huge appeal as Craig Overton strikes Nathan McSweeney in front. Somerset huddle quickly together and are reviewing the not out decision again.

Aatif Nawaz
Commentator on BBC Radio 5 Sports Extra

It was really close when looking at it because you could see a little bit of the off-stump exposed.

Nathan McSweeney is in and his first ball from Riley Meredith thuds into his pads.

Northants scamper through for a quick two before McSweeney nudges a single to mid-wicket. A good over for Somerset with the wicket of Ricardo Vasconcelos.

Chris Lynn still hasn't faced a ball yet.

Australian pace bowler Riley Meredith with the second over for Somerset and his first ball is flashed away hard by Ricardo Vasconcelos behind square on the offside for four.

Then a big appeal as Vasconcelos attempts the ramp and is caught at leg slip. Did it hit the bat or was it lbw? Somerset are asking the question.

Nice start for Northants from the first ball as Ricardo Vasconcelos flicks Craig Overton off his legs for four. That should settle any early nerves.

Vasconcelos then walks down the track to the fourth ball and flicks into the legside again to pick up another two.

And then a beautiful stroke for the second boundary of the innings, Vasconcelos pushing through extra cover on the up and it races away for four.

A quick single to end the first over and the Steelbacks will take that.

The pyro show greets the two sets of players as they take to the field and now away we go at Edgbaston for the highly anticipated T20 Blast Finals Day.

Northamptonshire Steelbacks, who have the most wins in the competition so far, against Finals Day regulars Somerset. This should be good.

Somerset's Headingley hero Craig Overton will bowl the first over for Somerset. Ricardo Vasconcelos and Chris Lynn opening up for Northants.

Melissa Story
Commentator on BBC Radio 5 Sports Extra

It's been scorching these past few weeks and certainly these are the conditions you want when you are locked in for a long day of cricket.

There are people who have travelled here from all over the country and we can see an array of county shirts in display, even for teams who haven't qualified because this is the day for county cricket.

Image source, Getty Images

We are settling in for a long, sunny and super Saturday of T20 Blast cricket.

And there's nothing more we'd like than to hear from you on any Blast or cricket-related matter. Simply hit that yellow button and share your thoughts with us.

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Somerset have won the toss and elected to bowl.

Northamptonshire Steelbacks have made one change from their quarter-final win over Gloucestershire with Luke Procter coming in for George Scrimshaw.

Somerset have also made one change from their dramatic last-over victory at Yorkshire in the last round, with ex-England spinner Jack Leach replacing Lewis Goldsworthy, who is out with concussion.

Tom Banton, who was released by England to play but only managed one from five balls with the bat in the last eight, also starts again.

Here are the two line-ups for our first semi-final of the day.

Northamptonshire Steelbacks: Ricardo Vasconcelos, Chris Lynn, Nathan McSweeney, David Willey (c), Saif Zaib, Louis Kimber, Calvin Harrison, Lewis McManus (wk), James Sales, Luke Procter, Ben Sanderson.

Somerset: Will Smeed, Thomas Rew (wk), Tom Banton, Tom Kohler-Cadmore, James Rew, Lewis Gregory (c), Daniel Sams, Craig Overton, Jack Leach, Riley Meredith, Jake Ball.

Image source, Getty Images

Defending champions with their backs seriously against their walls on Wednesday night?

Argentina? No, they were only one goal down in the World Cup semi-final.

For a true heroic comeback, we're talking Somerset and their two-wicket victory over Yorkshire in the T20 Blast quarter-final.

At 59-7 and 82-8, they were toast. Cue Craig Overton smashing 79 off only 30 balls to lead them to a two-wicket win off the penultimate ball.

After eight games of the group, they had lost five and were in big trouble of elimination but the Cider Boys have now dug out five straight wins and arrive at Edgbaston full of momentum.

Like Lionel Messi and Co, Somerset do not know when they are beaten and they are chasing history.

No side has defended the T20 Blast while a third in four seasons would take them to a record four Blast crowns.

Would you back against that?

Image source, Getty Images

As one of the smaller counties on the circuit, it's very easy for Northamptonshire to slip under the radar.

But in the last two seasons under grizzled ex-Australia head coach Darren Lehmann, the Steelbacks have started to punch above their weight again.

They returned to Finals Day last year for the first time in nine years only to lose to Hampshire Hawks in the semi-final.

But they were impressive winners of the Central and West Group this season (although they were twice well beaten by Somerset) and saw off Gloucestershire in the quarters with a bit to spare.

Australian T20 specialist Chris Lynn has smashed two centuries, while James Sales and Calvin Harrison have combined for 41 wickets with the ball.

Twice before (2013 and 2016) have Northants performed a heist at Finals Day and walked away with the trophy. Could this be an unlikely hat-trick?

BBC Local Radio

We have it all covered from Edgbaston where there is live commentary of all three games on BBC Radio 5 Sports Extra.

There will also be live coverage on the local stations with BBC Radio Northampton and BBC Radio Somerset now and BBC Radio Solent and BBC Radio Nottingham this afternoon for Hampshire Hawks v Notts Outlaws.

Image source, Shutterstock

• Northamptonshire Steelbacks v Somerset (11:00 BST)
• Notts Outlaws v Hampshire Hawks (14:30)
• FINAL (18:45)

Image source, Shutterstock

The party's been in the diary for months, but we only got the guest list on Wednesday.

We've reverted back to high summer from the creeping autumnal nights of September, so forget about needing a coat.

It's sunhats, suncream and cold drinks at the ready as T20 Finals Day is here.

Four sides have made it to Edgbaston for three high-octane games before the winners are eventually crowned around 10pm this evening.

So, let's go and have a Blast, shall we?