Last gasp goals from substitute Edin Dzeko and Sergio Aguero ensured Manchester City were crowned Champions for the first time since 1968.
A dramatic afternoon at the Ethihad Stadium saw City take a first-half lead courtesy of a rare Pablo Zabaleta goal.
But QPR levelled after the restart when Djibril Cisse slammed an equaliser before Joey Barton was sent off for an altercation with Carlos Tevez.
City were on top, but QPR were defending bravely until Dzeko responded to give them hope and then Aguero pounced with a delightful winner.
Manager Roberto Mancini admitted it was a 'crazy' occasion. "It was incredible - they deserved this. To win it like this is incredible. I don't think I've ever seen a finale like this.
"We didn't deserve to lose, we had a lot of chances and we deserved to win the game and championship.
"It's fantastic for the club and the supporters after 44 years. It's been a crazy season and a crazy last minute."
"Five minutes from the end, I didn't think we'd win this game. But we deserved to win this and deserved to win the title. We were on top for 20 games.
"I think for us it was really important to start winning this championship, Manchester City can have a big future now.
“This is a great day for City and most of all for the supporters. It has been 44 years since this club last had their hands on the title and everyone at City knows that is too long. We did it the hard way, but I am told that is the City way
“The supporters have never lost faith or patience - even in the last five minutes and we are so pleased that this season, we have delivered some history for them.
“Manchester United is a great club and a great opponent and to have come out on top in a fight for the title with them is fantastic.
“Every week the ground is full and the noise for the team is huge. I have said many times this season that no one should underestimate the help that players get from having a crowd supporting them in this way. It drives us on when things are possible not going so well.
“I am so proud of the players too. They fought hard all season and now can see the rewards. Hopefully this will be just the start of days like this. We set out to make history and that is what we have done.”
City skipper Vincent Kompany was thrilled with the character City showed under real pressure during a thrilling climax.
"You want to say it's the best moment of your life but, if I'm honest, please never again this way. Even though the first half was really good we just couldn't get through."
"I never stopped believing. When Edin scored that goal, it reminded me of so many other moments during the season when we've done this before. There was no reason not to believe. It's not sunk in yet. I don't know what happened at the end, it was just a huge mess.
"I'm so happy for the guys because they've given so much this season. We've dreamed of this all our lives and now we're champions. See the fans and how happy they are it is unbelievable."