Novak Djokovic defeated defending champion Rafael Nadal 6-4, 6-2, 6-7 (3/7), 6-1 to clinch the US Open in New York.The world number one Serb, who had already won the Australian Open before defeating Nadal at Wimbledon, racked up his 64th win yesterday against just two losses all year. Nadal a 10-time Grand Slam title winner slumped to his sixth defeat in six meetings in 2011 against Djokovic.The red-hot Serb eventually triumphed in a four-hour, 10-minute final featuring breathtaking shot-making, rock-solid defence and grueling rallies.