Juan Martin del Potro staged a superb comeback, fighting off illness and saving two match points as he beat Dominic Thiem in five sets at the US Open on Monday.
The Argentine 24th seed, who battled with illness early on and called for the trainer in the opening set, rallied to win a titanic battle 1-6, 2-6, 6-1, 7-6 (7-1), 6-4 to set up a mouthwatering quarter-final clash with third seed Roger Federer.
After his victory, Del Potro credited the fans courtside for lifting him to fight back and defeat Thiem.
"I was thinking to retire in the middle of the second set because I couldn't breathe, I couldn't move well," said Del Potro.
"Dominic was dominating the match so easy."
"Then when we started the third set, I broke his serve very quickly, and then I won the set in 20 minutes.
"And then it was another story. I started to see the crowd. I took all the energy from the fans. That's what I did and in the end, I just kept fighting. I didn't give up any point from the third until the fifth set."
Del Potro took the fourth set tiebreaker after earlier saving two match points with two aces. Then in the final set, his flat forehand was the big difference between the two players to hand the 28-year-old victory.
"I know people like it when I hit hard with my forehands. People stand up from their chair when I hit good winners," said Del Potro.
"I like to do that. But it doesn't happen very often. When I feel that confidence to do my best shots, I know I can be dangerous for all the guys."