The undisputed King of Clay, Rafa Nadal, could soon extend his reign to the hard court after establishing himself as the red-hot favourite for the US Open with back-to-back wins in Montreal and Cincinnati. With eight French Open titles, Nadal may be the best ever on the dirt but the Spaniard has also stood tall this year on the American hard courts, where he remains unbeaten with a 15-0 record. "On clay, we only had three [Masters events], I won two, and I played the final," Nadal said after grinding out a 7-6 (10-8), 7-6 (7-3) win over American John Isner in the final of the Western and Southern Open. "The results on clay were amazing. On hard, I play three, I won all three. Is only one more match. That's all. I think it's just a coincidence, but no doubt I am a better player on clay than on hard." Some would debate that assessment based on Nadal's play on the hard courts this season which - based on his record - has so far been flawless. To be fair, Nadal has already proven himself to be a man for all surfaces with grand slams titles on clay, grass and hard court. With the exception of grass and his opening-round slip up at Wimbledon, the Spaniard has impressed on all surfaces again this season. He added to his grand slam collection at the French Open and has captured five of seven Masters Series events, including three-of-four hard-court stops. The US Open has always been the hardest grand slam for Nadal because of its unforgiving surface and timing. Of his 12 grand slam titles, only one has come at Flushing Meadows and he only reached the final on one other occasion. Nadal usually arrives at the back end of the tennis schedule with his knees creaking like two rusty gates and nursing a mountain of aches and pains that are the payment for his relentless action-packed style. The ongoing battle with the debilitating tendonitis in his knees continues. But this year, after a long injury lay-off that bridged the end of last season and the start of the current campaign along with a six-week break following his Wimbledon exit, Nadal has arrived in the US ready for action. "If I am able to be healthy for the rest of the year, probably the rest is going to be positive," said Nadal. "For the last eight years before the injury, I didn't stop, I played every year long, very long seasons with very, very high intensity. "So mentally and physically, to have a period of rest and recovery, your body is great. Meanwhile, Victoria Azarenka toppled world No1 Serena Williams 2-6, 6-2, 7-6 (8-6) to claim the Cincinnati WTA title and establish herself as a contender for the US Open. "What doesn't kill you makes you stronger," said Azarenka who earned her 17th career title and first in Cincinnati. "It was a tough match and we both fought really hard. It was an incredible week for me. "I'm feeling very good. Obviously, it's a big win. It was a great match. I'm really, really pleased with the way I pulled it out. It was a great battle."