Leeds new signing Nick Barmby took 15 minutes to make an impact, scoring the opener as Manchester City lost their opening game of the season at Elland Road.
Nicolas Anelka missed City's best chance of the half as the visitors held their own after the setback, with skipper Ali Benarbia pulling the strings.
However, Leeds doubled the lead right on the break thanks to Mark Viduka's neat finish and Robbie Keane completed the victory late in the game.