PAUL McMULLAN grasped Dundee United a first-leg advantage as a controversial red card raised temperatures in the SPFL Premiership play-off semi-final.

Caley Thistle’s management team were furious at Liam Polworth’s early second half sending off after the midfielder seemed to catch United’s Mark Connolly with a high boot.

The hosts went agonisingly close several times in the first half but their resistance cracked with 12 minutes left in an even contest as McMullan hammered in the winner.

It remains all to play for at Tannadice on Friday, but home manager John Robertson was furious at the “match-changing” decision by referee Nick Walsh.

Robertson said: “It’s not a red card although I can understand why he’s given it. He’s saying serious foul play.

“But he’s not led with the sole of his boot, it’s his toe. Connolly’s put his head down and all Liam’s trying to do is nip it over his head wit his toe.

“The annoying aspect is he was blowing for a foul for us after Charlie Trafford is fouled. He goes to give us a foul but thinks Liam is going to win it and lets play go on.

“That’s the annoying thing – if he’d blown for the original foul it doesn’t happen.

“But that’s Nick Walsh – he wants to be the star of the show and unfortunately he is star of the show again.”

The hosts were stepping out for their seventh game in just under a month, three days after seeing off Ayr United’s quarter-final challenge.

United, in contrast, were back in action after the luxury of a restful 10-day break.

Personnel shortages forced manager John Robertson to change system to a back three.

United’s first attack saw Peter Pawlett thread an angled pass through to Osman Sow, who nicked the ball between home defender Coll Donaldson’s legs and then drew a strong save from Mark Ridgers down low.

But, after a flat finale against Ayr, there was an energy to the hosts and Joe Chalmers swung a deceptively lazy left foot at the ball 25 yards out and saw it bounce just wide.

The home side were then desperately unlucky not to open the scoring after 23 minutes.

Chalmers’ cross from deep left had big striker Jordan White towering onto a header that struck the inside post and rebounded to safety.

United were always dangerous on the counter, though, and a mis-timed Kevin McHattie header near the angle of the home box allowed the lively Paul McMullan an angled strike.

Keeper Ridgers reacted superbly to push it for a corner.

If McMullan was warming up for United, Caley Thistle’s creative talent Aaron Doran soon looked in the mood.

Among several threatening darts forward, the Irishman dispossessed Mark Connolly powered forward and swept in a low cross which the sliding Whie only just missed.

Polworth’s burst of pace and cross from the right produced another White header, clutched by Siegrist, before United finished the first half on the front foot.

After a promising first half, disaster struck the hosts inside three second half minutes.

Motherwell-bound Polworth, stretching a high foot for the ball, caught Mark Connolly in the face and took a straight red card for the reckless lunge.

Depleted, the hosts’ forward momentum ebbed. United, though, were slow to capitalise. Then came the 78th-minute breakthrough.

The ball broke to Clark at the edge of the box and a right foot smash rebounded off the foot of the post, spinning to the right side of the penalty area.

There was Paul McMullan, sharp onto it in reaction, to calmly sweep in the rebound off the inside of the left hand post.

A delighred United manager Robbie Neilson said: “This was always going to be a very tough game, there was an edge to it and there was a nervousness.

“The tie is far from over, Inverness will come to Tannadice with nothing to lose and have all guns blazing.

“We are just glad to see tonight out and get a bit of a cushion.

“A few of the lads are feeling the rigours of tonight and we’ll need to get them ready for Friday now.”