With the grandstand crowd roaring in support, Del Potro saved two match points in the fourth before sealing the win
Roger Federer and Rafa Nadal stayed on course for a possible US Open semi-final showdown with victories on Monday’s eighth day of the competition, while ailing 2009 champion Juan Martin del Potro edged a thrilling five-setter to make the last eight at Flushing Meadows.
Suffering from the flu, the towering Argentine took some medication early in the match against Austrian sixth seed Dominic Thiem, who won the first two sets.
Saving two match points in the fourth set and with the Grandstand crowd roaring him on, Del Potro completed the comeback, sealing a 1-6 2-6 6-1 7-6(1) 6-4 win.
“Oh my God, I don’t know (I won). What can I say after a battle like this. I was sick the last two days and I just tried to improve game after game,” Del Potro said after his match.
“I fought like this because of you guys, so thank you very much,” he added, pointing to the Argentine fans in the crowd.
Del Potro now faces Federer, whom he beat in the final in New York for his only Grand Slam title.
The Swiss third seed took an easier route into the quarter-finals, firing 11 aces and 39 winners as he despatched Germany’s Philipp Kohlschreiber 6-4 6-2 7-5 in one hour, 45 minutes.
The only worry for Federer would be the condition of his back after he left the court midway through the match for treatment. The Swiss, who started slowly at New York due to the niggling issue, allayed fears after his match.
“I just felt something, sort of my muscle being tight at the back,” said Federer. “I wanted to get it done really quickly after the set break. It was more precaution. It’s all good. No problems there. I’m not worried about it.”
World number one Nadal made short work of Alexandr Dolgopolov 6-2 6-4 6-1 and the French Open champion now faces Russia’s Andrey Rublev, after the 19-year-old knocked out ninth-seeded Belgian David Goffin 7-5 7-6(5) 6-3.
The 19-year-old Rublev became the youngest US Open men’s quarter-finalist since American Andy Roddick in 2001.
Nadal, meanwhile, is on course to win his second Grand Slam of the year after sealing the French Open title in June.
Women’s top seed Karolina Pliskova of the Czech Republic routed American Jennifer Brady 6-1 6-0 to set up a match with American 20th seed CoCo Vandeweghe who beat Lucie Safarova 6-4 7-6(2).
American Madison Keys smashed 46 winners but also committed 52 unforced errors in her 7-6(2) 1-6 6-4 win over Ukraine’s fourth seed Elina Svitolina.
The 15th seed now faces world number 418 Kaia Kanepi of Estonia who cruised past Russian Daria Kasatkina 6-4 6-4.