LONDON - Reigning champions Manchester City celebrated manager Roberto Mancini’s 100th Premier League match in charge with a 3-1 victory at home to Queens Park Rangers on Saturday.Yaya Toure gave City a 16th minute lead at Eastlands when he scored from close range following a corner.But Italian boss Mancini would have been fuming when QPR, managed by his City predecessor Mark Hughes, equalised against the run of play in the 59th minute.England goalkeeper Joe Hart could only parry a fierce drive from Andy Johnson and Bobby Zamora headed into an empty net.But parity lasted just two minutes with Edin Dzeko heading in an excellent Carlos Tevez cross.Argentina striker Tevez put the result beyond doubt in stoppage time when he deflected in Dzeko’s wayward shot."I think we played well in first half but we have one problem at the moment and that’s that when we have a chance to score we don’t,” Mancini told the BBC. "I said it is important that we improve because we can’t concede a goal in every game.”