Juan Martin del Potro shrugged off sickness to save two match points and defeat Dominic Thiem in a five-set US Open epic on Monday to book a quarterfinal showdown with five-time champion Roger Federer.

Argentina 24th seed Del Potro claimed a heroic 1-6, 2-6, 6-1, 7-6 (7/1), 6-4 victory over the sixth-seeded Austrian on a rocking Grandstand court, describing it as night he would remember forever.

Del Potro famously defeated Federer in the 2009 final for his only career Grand Slam title before his career was almost torpedoed by a succession of wrist surgeries.

Federer, the third seed, eased into the last-eight with a 6-4, 6-2, 7-5 win over Philipp Kohlschreiber, taking his record over the German veteran to 12-0.

Elsewhere, top seed Rafael Nadal claimed his 50th win at the US Open and will meet Russian teenager Andrey Rublev.

In the women's event, world number one Karolina Pliskova set-up a quarterfinal date against America's CoCo Vandeweghe.

Estonia's world number 418 Kaia Kanepi also reached the quarterfinals, just the second qualifier to make the last eight.

But the day belonged to Del Potro, who celebrated his win, which came off a Thiem double fault, by stretching out his arms, head facing the night sky, as his legion of fans, many dressed in the light blue colours of Argentina's famed football and Pumas rugby teams, celebrated wildly.

"Oh my God," said Del Potro, who had been 2-5 down in the fourth set. "I was sick the last two days. I came here trying to play the best I can and then when I see this crowd cheering for me, I was trying to play better every game. I will always remember this."

Federer has a 16-5 advantage over Del Potro but they have split their last six meetings. The 36-year-old Swiss maestro didn't face a break point against Kohlschreiber with his biggest challenge having to take a medical time-out off court at the end of the second set.

World number one and 2010 and 2013 champion Nadal crushed Ukraine's Alexander Dolgopolov 6-2, 6-4, 6-1. The 31-year-old Spaniard goes on to face Russian 19-year-old Rublev, who stunned Belgian ninth seed David Goffin 7-5, 7-6 (7/5), 6-3 to become the youngest quarterfinalist since Andy Roddick in 2001.

"I played a solid match with not many mistakes," said Nadal, the reigning French Open champion.

Rublev, ranked 53, has won 13 of his last 17 matches after breaking the top 100 for the first time in June.

"Rafa is a real champion. I will try to do my best - I have nothing to lose," said Rublev.

Source: Khaleej Times