BEIJING – World No 2 Novak Djokovic said on Monday his conqueror in the US Open final this year Andy Murray has the "quality” to be a contender at every Grand Slam the Scotsman plays in.Murray’s 7-6 (12/10), 7-5, 2-6, 3-6, 6-2 victory over the Serbian was his first Grand Slam victory in five finals appearances with world No 1 Roger Federer and Spain’s Rafael Nadal winning 29 of the prior 30 major titles."Murray, I think, is playing better than ever,” Djokovic said in Beijing ahead of his first round tie at the China Open."He won his first Grand Slam title. I’m sure that he’s one that’s going to be, in the future, one of the contenders to win every Grand Slam he plays in."He definitely has the skill, the quality,” added the five-time Grand Slam winner who is looking to extend his unbeaten record at the China Open.Djokovic has won the event on the two occasions he has entered it, in 2009 and 2010, but missed last year because of injury."I really, really want to do well here,” he said. "I won the bronze medal in these courts (at the Beijing Olympics in 2008), so I have really nice memories from this tournament.”