Tony Docherty praised his Dundee side for going toe-to-toe with a "top-class" Hearts side but admitted he is "perplexed" over Nick Walsh's decision to change his mind over a first-half penalty decision during the 3-0 loss at Tynecastle Park.

The official awarded the visitors a penalty at 1-0 when Lyall Cameron's shot was adjudged to have been blocked by Stephen Kingsley's elbow. The Hearts defender was adamant the decision was wrong. Walsh was called to the monitor by VAR and altered his decision, awarding Dundee a corner.

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"I was really pleased with the team performance and I don’t think it is a 3-0 game," Docherty said. “We went toe-to-toe with them but I think we made two mistakes. To me the pivotal moment in the game was the decision not to give the penalty kick. I’m perplexed at that.

“If you look at the fixture at Dens, there is an identical situation where the ball strikes Lee Ashcroft on the hand and that penalty is given. That’s where the frustration comes. It is 1-0 and we have done very well, I’m pleased and I’m confident Luke McCowan goes and scores that penalty. Then it’s game on.

“It has been too many times when decisions have gone against us and the inconsistency frustrates not just me, but every football manager.”

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Docherty did not receive an explanation from Walsh but said he was "right behind it"

"When he gave it, I thought it was a penalty kick. The arm is out. I don’t think the camera angles are clear from what I’ve seen. For such a pivotal decision in a game at 1-0, you need to be sure.

“I can only base it on experience from the identical situation at Dens. Why is one a penalty and the other is not? The referee is on the pitch, he smells it, he feels it. Everyone in our dugout thinks it’s a penalty kick. We’re re-refereeing the game.”

Dundee face a steep challenge to overturn a five-point gap to St Mirren in fifth to achieve European football. Docherty, who was full of praise for Hearts, is not for throwing in the towel.

"As long as we've still got an opportunity to do that, we'll do it," he said. "There's disappointment among the boys but I've tried to lift them. With the level of performance we got, the players should be leaving here with their chests puffed out. That's the reason we're in the top six, to play against top-class opposition, which Hearts are. Naisy's done a brilliant job with them but I thought we went toe-to-toe with them. I'm disappointed with the first two goals we lost."