Spurred on by noisy supporters after two days of illness, Juan Martin del Potro saved two match points Monday to outlast Dominic Thiem in an epic five-set thriller to reach 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 for his second career victory after falling two sets down.

“I play one of the epic matches of my career here in the US Open, which is my favorite tournament, in front of a great crowd,” Del Potro said.

Supporters wearing Argentina football jerseys and chanting “Ole, Ole, Ole” urged on their weary hero from the brink to a stunning endurance-test triumph, creating a Davis Cup-like atmosphere.

“I was sick the last two days,” Del Potro told the crowd.

“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 admitted he was ready to quit when it seemed Thiem would win in a rout, but as his will faded, the crowd lifted him onward.

“I was thinking to retire in the middle of the second set because I couldn’t breathe, I couldn’t move well. Dominic [Thiem] was dominating the match so easy,” he said.

“But then when we start the third set, I broke his serve very quick, and then I won the set in 20 minutes. I starting to see the crowd. I took all the energy from the fans. That’s what I did in the end, just keep fighting.”

Del Potro won the last point with his final challenge, reversing a Thiem second serve call to out.

“I was scared for that ball,” he said. “But I got lucky, the ball was out, and I won.”

Then the South American star looked up and raised his hands to the heavens as a thunderous ovation erupted.

“I got exhausted after the last point of the match. That’s what I did with my hands, looking the sky,” Del Potro said.

“I’m so glad to go through. I played a fantastic battle against one of the best players on the tour.”

Del Potro will next face 19-time Grand Slam champion Roger Federer, whom he beat in a 2009 five-set final for his only Grand Slam title.

“I have the chance to play Roger again in this tournament, which is special for me,” del Potro said, adding, “I would like to have the trophy after these matches.”

Del Potro hopes to recover in time to create more special moments in Arthur Ashe Stadium.

“I feel tired. But we cannot do magic,” Del Potro said. “Just massage, some physical movement with the trainer. But hopefully my day off I can recover a little bit more.”

‘I will always remember’

In Spanish, Del Potro told his fans he would never forget their inspiration.

“Thank you very much from the heart for the support you gave me,” Del Potro said. “Was very useful to not abandon, not to give up, and this match I will always remember.”

Nagged for years by wrist injuries, Del Potro has become a fan delight with his mild manner, powerful shot-making and grit.

“People loves my effort to come back. They know what have been through with all my wrist problems,” he said. “They like a guy who never give up.”

Theim said his game was not thrown off by the passionate support for del Potro.

“I was enjoying it. The crowd didn’t affect the result of this match.”