Bryan Robson felt Sheffield United's 2-1 FA Cup win over Manchester City was the ideal tonic for the Blades after last weekend's derby defeat.The Blades' first goal in Sunday's fourth-round tie at Bramall Lane was slightly bizarre as Lee Martin's left-wing cross took two deflections off balloons which had floated onto the pitch from the end the City supporters were occupying, wrong-footing Michael Ball and allowing Luton Shelton to sidefoot home.

Jon Stead put United 2-0 up and although Daniel Sturridge pulled one back within three minutes of coming on at the start of the second half, City could not find an equaliser.

"I thought we were terrific and we owed the fans that one," Robson said.

"We have been missing far too many chances but today they went in for us.

"I thought we matched them in every department and that is what the lads are capable of."

Robson admitted their first goal had a touch of luck about it but was happy to accept it.

"There was a bit of fortune about it. Today we did ride our luck at certain times but our counter-attack play was very good," he told Sky Sports.

Manchester City manager Sven-Goran Eriksson blamed referee Alan Wiley for not preventing the circumstances which led to the opening goal.

"It is a very strange goal because the ball changed direction. Two balloons made a one-two with Michael Ball. I have never seen a goal like that," he said.

"We asked the fourth official twice in the first half to tell the ref to stop it (the match) and clear it.

"I think the referee told Joe Hart (City's goalkeeper) that when the ball is in the other half of the pitch, he should clear it but I think that is not right - you should not ask a player when the ball is live to clear the pitch.

"But it would be stupid of us to say it (the defeat) was because of the balloons."

Eriksson was also critical of his players for lacking the stomach for a battle.

"I think we were not happy to take the fight as we should have done. We lost too many balls in midfield and up front," he told Sky Sports.

"It is the beauty of the cup which hit us today. If you are not prepared to battle, as well as play good football, you know a team from a lower division will fight well.

"We should do better. It is our fault in the first half, although second half we did well."

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