Gary Roberts is fouled by John Welsh and the game suddenly boils over with both sets of players getting involved in an angry confrontation.

There's plenty of pushing and shoving and Roberts even appears to have his hand around Paul Gallagher's neck.

Referee speaks to both involved parties and takes no further action. There's now a bit of an edge to this game.

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A lively start in both of our League One play-off semi-final first legs this evening. Sheffield United and Preston have the upper hand in their respective games at present - will it finish up that way? Or can either Swindon or Chesterfield respond?

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Ben Gladwin's in for a sleepless night.

Nathan Byrne weaves his way into the home side's penalty area and is tripped, prompting the referee to immediately puff his whistle and point to the spot.

Gladwin then fires his penalty low to the goalkeeper's right, but Mark Howard gets down well to parry it away and then fumble the rebound clear. Huge, huge let off for Sheffield United.

Swindon Town have a penalty!

Ian Woodcock
BBC Sport at Bramall Lane

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"Sheffield United manager Nigel Clough will be relieved that they've got the goal their start deserved. The hosts are getting through a lot of work and Swindon's midfield have hardly had the ball."

Swindon Town have picked up more points on their travels this season than Sheffield United have at home, which suggests to me this first leg is anything but over.

Ben Gladwin almost squirms clear in the penalty area for the Robins as the away side continue their recovery. We've got a game on.

It's certainly an open game so far. Just lacking a little bit of quality in the final third since Jermaine Beckford's sixth-minute goal.

So what can Mark Cooper's team do from here? They've actually responded quite well, to their credit, with Michael Smith absolutely smashing a shot from distance into Jay McEveley. He'll feel that one in the morning.

Chesterfield finally launch a meaningful attack. Tendayi Darikwa bursts down the right and launches in a fine cross which finds Gary Roberts, but his low shot is blocked by Tom Clarke.

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You can't say it's not been coming.

Ryan Flynn turns this way and that down the right, before eventually teeing up Kieron Freeman to drill a low shot pass Wes Foderingham, who gets a hand to it but can't keep it out. Sheffield United lead.

Preston continue to look threatening. Daniel Johnson chips a ball into the box which is acrobatically squared by Scott Laird to Joe Garner but his shot is blocked.

Ian Woodcock
BBC Sport at Bramall Lane

Image source, Getty Images

"The Blades are well on top here and Swindon are having to weather the storm. Robins manager Mark Cooper is looking pensive on the touchline, he'll want his side to do more to cut off the supply to Sheffield United's wide players."

My goodness, Sheffield United have bossed this opening 15 minutes and that was by far their best chance yet.

A cross-come-shot from the left is drifting well wide, but striker Steven Davies does excellently to get his right foot to it at the far post - only to scuff the connection.

A penny for Mark Cooper's thoughts? His side are under the cosh.

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Paul Cook's Chesterfield look a bit shell-shocked from that early Jermaine Beckford opener for Preston. The Proact Stadium has gone quiet and the Spireites are struggling to get into the game.

Now then, what have we got here? Jamie Murphy is the dangerman for Sheffield United again, getting to the byline down the left and pulling a cross back, only for it to strike the arm of Swindon's Ben Gladwin.

The referee waves away the appeals, suggesting his arm was down by his side. I'm not so sure - I reckon we can file that one under the 'seen them given' section.

Great link up play between Jermaine Beckford and Joe Garner. The goalscorer flicks the ball onto Garner who shoots straight at Tommy Lee from a tight angle. It's all Preston at the moment.

Paul Coutts has now won himself a slightly soft free-kick on the far side after a nudge from Ben Gladwin. What can they make of this?

Not much, is the answer. Chris Basham's attempt trickles into the arms of goalkeeper Wes Foderingham.

The Blades have certainly started on the front foot, as Jamie Murphy cuts inside onto his weaker left foot before shooting wide of the near post from inside the penalty area.

Plenty of empty seats inside Bramall Lane tonight, by the way. The famous Kop behind the goal is packed, as you'd expect, but other areas of the ground are looking pretty sparse.

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Jermaine Beckford puts Preston in front after some slack defending from the hosts. Chris Humphrey plays a through ball and Beckford is left all alone. The striker races onto it and slots a calm finish past Tommy Lee for his 10th goal in his last 16 appearances.

Sheffield United are in their familiar red-and-white stripes tonight, while the Robins are sporting a rather dashing purple, white and black kit. The home side have the first shot in anger, but it's blocked away.