Sir Alex Ferguson claimed Manchester City's opener should not have stood after Manchester United's title drive stalled at Old Trafford last night.
City's 2-1 win cut the Red Devils' lead at the top to 12 points and means they will have to wait at least another fortnight to claim a record 20th championship.
But the outcome might have been different had Carlos Tevez been ruled offside as James Milner's piledriver found the net, as Ferguson claimed he should have been.
"The first goal, the player is right in front of David de Gea," said Ferguson.
"There is no way the linesman on that side is giving it but if that is not interference I don't know what is."
Nevertheless, the Scot was not that surprised at City's first back-to-back wins at Old Trafford since 1972, given the nature of the club's past triumphs.
"If you look at the history of our club, we always make it difficult for ourselves," said Ferguson.
"We have our supporters hanging on the edge of their seats every year.
"We have a 12-point lead but we won't be taking anything for granted.
"The plus point from today is that we only have seven games left now. As each game goes along you whittle them down.
"We have Stoke on Sunday. The support will be great and we will have a go. We have to kick on now."
There does seem to have been an extended hangover from United's Champions League exit to Real Madrid last month, which was followed last week by an FA Cup defeat at Chelsea.
Ferguson will want his side to stabilise themselves before needless anxiety starts to take hold.
And, after 10 games without a goal, he could do with Robin van Persie getting one, even if it was the Dutchman's brutal free-kick that created the panic that ended with Vincent Kompany's equalising own goal.
"Robin was absolutely fantastic," said Ferguson.
"We were a bit lucky with the goal because it was an own goal off Kompany. But it was a fantastic free-kick."
Ferguson confirmed Ashley Young was a doubt for Sunday's trip to Stoke after coming off worst in a challenge with Pablo Zabaleta.
However, he is more concerned about bolstering his defensive strength, with Nemanja Vidic, Chris Smalling and Jonny Evans missing through injury.
"We want to get a centre-back fit," he said.
"That would be important for us."