New York, Sep 5 (IANS): Argentine tennis star Juan Martin del Potro saved two match points to outlast Dominic Thiem in a five-set thriller on Monday and set up a clash against Swiss third seed Roger Federer in the US Open quarter-finals.

The 28-year-old Argentine 24th seed rallied past Austrian sixth seed Thiem 1-6, 2-6, 6-1, 7-6(1), 6-4 in an emotional fightback, which is only his second career victory after falling two sets down, reports Xinhua news agency.

"Oh my God," Del Potro told the crowd after the match on the court. "I was sick for 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 think I fight like this because of you guys so thank you very much."

Del Potro, the 2009 US Open champion, will next face 19-time Grand Slam champion Federer, the Swiss third seed, who got past German 33rd seed Philipp Kohlschreiber.

Del Potro defeated Federer in a five-set final eight years ago here for his only Grand Slam title, when he also dispatched Rafael Nadal in the semifinals.

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

Top seed Rafael Nadal of Spain also got an easy win, beating Aleksandr Dolgopolov of Ukraine 6-2, 6-4, 6-1. He will take on Russian teenager Andrey Rublev, who upset ninth seed David Goffin of Belgium 7-5, 7-6(5), 6-3.

In the women's event, world number one Karolina Pliskova of the Czech Republic set up a quarterfinal date against American player CoCo Vandeweghe.

Estonia's World No.418 Kaia Kanepi also reached the quarterfinals, becoming only the second qualifier in US Open history to make the last eight.

She will take on Madison Keys from United States, who shocked fourth seed Elina Svitolina of Ukraine 7-6(2), 1-6, 6-4.