Paul Heckingbottom was relieved that Sheffield United’s winning goal at Sunderland was allowed to stand to keep his side ahead of the chasing pack in the Championship’s promotion race.

The Blades had fallen behind to Edouard Michut’s opener after half an hour when he drilled low inside the far corner with a fine finish.

But Sheffield United hit back through James McAtee when he curled inside the far post at the end of the first half.

And just after the hour Tommy Doyle’s free-kick appeared to bounce straight in from the left flank to give the visitors the lead.

Referee Matthew Donohue and his assistants allowed the goal to stand despite Sander Berge having been in an offside position and attempting to go for the ball before it dropped in the net.

The goal meant Sheffield United climbed six points clear of third-placed Middlesbrough ahead of this Sunday’s FA Cup quarter-final with Blackburn.

Heckingbottom, whose side lost to Luton at the weekend, said: “If I am Tony (Mowbray, Sunderland boss) I am claiming that. It is harsh on Tony, if I am seeing that, I’m spewing. But he is not blocking the keeper’s sight and there’s no touch, I don’t know the law.

“We were really bright, brave and sharp with the ball. To concede the way we did was a kick in the teeth. We showed good mentality to get back into it, the energy and bravery we wanted to show. I’m pleased with the response.

“We got the goal we deserved first half. The message was the same at half-time and I was pleased with how we did respond and played.

“I am proud of all the staff and players and how professional we have been. This week could be a huge week in careers for the players and the history of the club, that is what we are playing for. We can’t be fearful, we are in a fantastic position in the league and in the quarter-final of the cup.”

Sunderland manager Tony Mowbray was deeply frustrated by the outcome, knowing that the defeat has left his side eight points adrift of the top six with nine matches remaining.

He said: “We played against a good team, found it difficult to match them first half. They showed their experience and we knew they would.

“We scored a really good goal, the timing of their first goal was damaging for us.

“It would be great if the referee or linesman could come here and say why they allowed the second goal to stand.

“A member of our coaching staff has said the referee has apologised and said he got it wrong, which doesn’t mean much for us. I don’t even think it is in doubt, he is interfering with play. Between the two of them they have got it badly wrong and ultimately it has cost us.

“If people make a genuine effort to get the ball, he (Berge) missed it by millimetres, there’s even an argument it grazed his knee, and he started in an offside position.

“I have been in football since I left school and offside is offside. In my mind it shouldn’t have happened. We have to suffer the consequences.”