The Rs became the first side to go in front against City this season, thanks to Jay Bothroyd, and then levelled after the game had turned in City's favour with two goals either side of the break.
Even after Yaya Toure had headed home what turned out to be the winner QPR had chances, with Heidar Helguson hitting the bar and young striker Jamie Mackie failing to go down when Warnock felt he would have been granted a certain penalty.
"It is a diabolical result," said Warnock.
"Football can be a cruel game sometimes. You do not get what you deserve.
"We have made three errors in 90 minutes against a side I would regard as the best in the world, and got punished every time.
"The performance probably surprised a few people, but I think we can get even better.
"I guess you have to take it on the chin. It is results like that that make them champions elect."