The Chelsea and Arsenal managers have claimed Manuel Pellegrini's team has benefited from good fortune in key games after two contentious decisions helped them past Tottenham
City cruised to a 5-1 victory against Tottenham on Wednesday but Tim Sherwood's team saw a Michael Dawson equaliser controversially disallowed and have now had a red card awarded to Danny Rose - for a foul which resulted in a penalty - overturned.
The two rival bosses admitted the quality of Manuel Pellegrini's team was unquestionable but contend that certain decisions have swung important games in their favour.
"I think they have everything," Mourinho told reporters. "The players are obviously very good. On top of that - and I want to make it very clear that, for me, it is just a coincidence and nothing else - the reality is they have had many crucial decisions in their favour. They are lucky.
"Against Liverpool, the Sterling 'goal', the penalty on Suarez. Against Newcastle, the [disallowed] goal that is a clear goal. Against Tottenham, Dawson's goal, the penalty, the red card [for Rose]. They are having everything.
"I repeat: just pure coincidence. The referees try to do their best, and sometimes they make mistakes. But at the moment they have everything in their favour. But it's just a coincidence. The players and team are very good, and the manager is working very well."
City's thrashing of Spurs was less convincing than it first appeared when put under the microscope, Wenger added.
"At the moment, they are on fire," the Arsenal boss said. "But people are always tempted to go to definite conclusions after one game.
"Of course they had an impressive win, and a great quality game at Tottenham. But if you analyse it well, this game could have turned. All the turning points went in their favour. If they had not, you are not sure they would have won the game."