Juan Martín del Potro pulled off one of tennis’s most remarkable comebacks to reach the quarter-finals of the US Open.

The 2009 champion has been struggling with illness and won only three games in the opening two sets against sixth seed Dominic Thiem. It seemed doubtful whether Del Potro would even be able to complete the match but he did much more than that.

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The Argentinian raced through the third set, saved two match points with aces in the fourth and then clinched the fifth to win 1-6, 2-6, 6-1, 7-6 (7-1), 6-4. At his moment of victory, after HawkEye showed that Thiem had served a double fault, Del Potro stood with head back and arms aloft as his legions of supporters on Grandstand roared.

On-court interviewer Pam Shriver had to wait for the ‘Ole’ chants to die down before posing the question of just how he was able to win the match. “Oh my God,” said the 22nd seed. “I don’t know what can I say after this big battle. I was sick the last two days. I came here trying to play as well as I can. When I saw all of this crowd cheering for me, my illness cleared up. I was trying to feel better every game. I fight like this because of you guys.”

Play Video 1:32 Del Potro relishing US Open quarter-final with 'greatest guy in history' Federer – video

Del Potro must now try to recover for a quarter-final meeting with Roger Federer, who he beat to win his only grand slam title eight years ago. The Swiss beat Germany’s Philipp Kohlschreiber 6-4, 6-2, 7-5 later on Monday.

“I would like to have the trophy after these five matches,” said Del Potro with a smile. “I’m so happy to go through after playing this great match. I enjoyed it a lot. I think it’s enough for me but maybe I have the chance to play Roger again, which is special for me, and I would like to play my best tennis.”

Del Potro looked exhausted at the start of the match and called for the doctor, who gave him some pills. They finally seemed to kick in for the third set, when Del Potro found his heavyweight punch of a forehand and began to land some blows on Thiem.

The Argentinian broke early in the fourth set but back came Thiem and, when he led 30-0 serving for the match at 5-3, the comeback seemed over. But Del Potro threaded a backhand pass down the line to give himself hope and with that Thiem blew his chance, hitting two wild errors and a double fault.

It was tough on the young Austrian, who must have felt as if he was playing an away Davis Cup tie, but he dug in and had two match points at 6-5 only for Del Potro to send down aces. The 28-year-old ran with his momentum in the tie-break, ending it with a forehand cross-court bullet that took the breath away.

Del Potro looked like he might have missed his chance when Thiem bravely saved three break points at 3-3 but, serving to stay in the match, his resistance ran out. It was a story of two HawkEye challenges; the one Thiem was unable to make because he had run out on the penultimate point when a forehand was called wide, and the one Del Potro successfully made on Thiem’s second serve.