And it's gone for four! So much of his power comes from that bottom hand, greeting a decent delivery with hard hands and shovelling a drive past AB De Villiers. That's a remarkable shot.

Bairstow ends up on his backside as he ducks a vicious short ball from Morne Morkel - but that's a no ball from the South Africa! Morne has falling victim to the Steven Finn rule, knocking the bails off at the non-striker's end. Free hit coming up...

Vic Marks
Ex-England spinner on BBC Test Match Special

Jason Roy, when he comes off, makes a run-chase or setting a target easy. He doesn't always come off but that's part of the deal.

Jason Roy raises his bat as the Taunton crowd applaud him. This is his second half-century in Twenty20 cricket for England. He's found his form at the right time.

50 for Roypublished at 10.5 overs

10.5 overs

Eng 100-1

Wrist spinner Tabraiz Shamsi is on. How will Jason Roy deal with him? He has a big swipe at his first delivery and just about avoids inside edging onto his stumps. Shamsi has a long, almost diagonal, run up for a spinner, and Roy slaps the ball to cover for a single. That's better from Roy, a straight six, the ball spinning into the stands, to bring up his half-century.

Adam Mountford
BBC Test Match Special producer

Image source, PA

Stuart Broad has been ruled out of Nottinghamshire's day-night County Championship match with Kent which starts on Monday - but is hopeful he can play at Lord's in the Royal London One-Day Cup final on 1 July.

The England seamer was forced off the field with a bruised left heel on Wednesday after bowling just one over in the second innings of Notts' three-day victory over Leicestershire.

Broad has undergone an assessment to ascertain the extent of the damage, but it is not clear yet if he will be back for the showpiece final against Surrey.

He will also hope to be fit to play for England against South Africa, also at Lord's, starting on Thursday 6 July.

After watching his short ball get absolutely hammered for six, Morne Morkel changes tactics and hurls down a yorker that Bairstow blocks away for a single.

AB keeps mixing the bowlers up and chucks the ball to Morne Morkel. He goes short and Bairstow pulls, misses and the ball flies away over his head for four byes. He's got hold of that one though - six! That was off the middle of the bat and it was slapped hard into the crowd.

Vic Marks
Ex-England spinner on BBC Test Match Special

These are great shots from Jonny Bairstow, with minimal risk.

That's a shot and a half from Jonny Bairstow. He takes a step down the wicket, giving himself room to get to the pitch of the ball and driving up and over the covers for four. Glorious, not allowing JJ Smuts to settle, and that's a costly over for South Africa.

JJ Smuts is going to bowl some left-arm spin, and Jason Roy decides to reverse sweep his first ball. That's a horrid-looking shot, the ball billowing up into the air off a top edge, but it lands safely with not a fielder in sight. Bairstow opts to play a little more safely before opening his arms and driving the ball up and over the fielders at long-off.

Vic Marks
Ex-England spinner on BBC Test Match Special

Bairstow plays in an orthodox way - he's not into the scoop over the shoulder - and he knows when he hits it, he has enough power to get to the boundary.

Jonny Bairstow decides he likes the look of this scoring boundaries business. That's a beautiful straight drive, clubbed hard back past the bowler for four. And again! This time it's slightly more of a club from Bairstow, giving the ball a bit of air and hoicking the ball over the bowler's head.

Short from Andile Phehlukwayo, and Roy responds with a vicious pull along the ground for four. That was almost a tennis forehand from Roy, fast hand-eye co-ordination letting him swipe the ball away with aplomb.

Dave Wood‏: Bairstow in the absolute form of his life. Sweet cover drive.

Jason Roy comes haring down the wicket and has a wild slog at Dane Paterson, who hurls down a bouncer to stop him. He looks at the umpire to make sure it's not been signalled a wide, before Roy nurdles a single away. This is a tidy over from the South Africa seamer, and England can only work four runs from it.

Ebony Rainford-Brent
Ex-England batter on BBC Test Match Special

Image source, Rex Features

England are cruising nicely - if these two continue, the match will be over and done with pretty quickly.

Here's right-armer Andile Phehlukwayo and he surprises Bairstow with a shorter delivery that rises up at him. Jason Roy then clubs a sure-fire boundary that is cut off by a superb bit of fielding by a diving Reeza Hendricks. Up in the dressing room, new boy Liam Livingstone has his helmet on, ready for action.

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