<p><br /> Top seed Rafael Nadal displayed all his renowned fighting spirit to beat Denis Istomin and complete the third round line-up at the US Open.<br /> </p><p><br /> Nadal cruised through the opening set against the in-form Istomin - who reached the final in New Haven last week - on Arthur Ashe Stadium, but found himself 5-1 down in a second-set tie-break.<br /> </p><p><br /> But the world number one dug deep to somehow win the next six points in a row - one of them with a lucky net cord - on his way to a 6-2 7-6 (7/5) 7-5 victory in two hours and 44 minutes.<br /> </p><p><br /> Nadal, who needs to lift the title on September 12 to complete the career Grand Slam, paid tribute to a gutsy performance from Istomin, the world number 39 deserving to at least take the match into a fourth set.<br /> </p><p><br /> "He was playing really well," Nadal admitted. "He had a great tournament last week and so he was playing with confidence today and I was a little lucky in the tie-break.<br /> </p><p><br /> "I started the match well, my serve keeps working well but every match is really difficult."<br /> </p><p><br /> One of Nadal's serves was clocked at 134mph, well down on the likes of Andy Roddick perhaps, but certainly one of the fastest the Spaniard has ever produced.<br /> </p><p><br /> "I am working on my serve all my life, sometimes it works well, sometimes it's not working all that well," Nadal added. "A few days ago I started to feel very well with my serve and the first two matches I have not lost my serve which is very good for the confidence."<br /> </p>
