Juan Martin del Potro progressed to the semi-finals of the US Open with a stunning 7-5 3-6 7-6(8) 6-4 victory over Roger Federer.
Coming off the back of a superhuman effort to beat Dominic Thiem over five sets, Del Potro was the clear underdog coming into the match.
However, after sharing the opening two sets with his opponent, Del Potro rallied in the third to win via a tie-break and then found a crucial break in the fourth to secure victory.
It was a match akin to Federer and Del Potro’s thunderous clash in the 2009 US Open final, which the latter won, and he goes into Friday’s semi-final with Rafael Nadal full of confidence, if not energy.
While Del Potro’s ability to dig deep when it mattered and his incredible service game and forehand combo will be rightly praised, there must be question marks about Federer’s performance.
Having suddenly kicked into gear in the last couple of matches, Federer looked off the pace and could only produce moments of magic in isolation with no consistency.
With both players serving out comfortably in the opening set it took a special game from Del Potro to break, winning the 11th with some sensational forehands that left Federer scrambling around the court. It set up an opportunity to take a surprise lead, with the 24th seed doing exactly that.
Federer started the second set much better and found an elusive break in the fourth game as he started to move Del Potro around and, crucially, targeted his backhand. As Del Potro started to show some signs of fatigue Federer began to take control, taking the second set with relative ease.
The Swiss maestro looked set to coast home.
But the third set was an incredible topsy-turvy affair as Del Potro suddenly came back to life and raced into a 3-0 lead. However, Federer fought back brilliantly to force a tie-break.
Even then the two could hardly be separated as Federer blew four set points before – eventually – Del Potro’s tremendous guts reaped dividends with a 10-8 tie-break triumph.
It was a common theme as throughout the match Del Potro managed to summon winners at crucial moments, despite being far from 100 per cent with a virus still clearly troubling him.
One such moment saw him break in the fifth game of the fourth set to move ahead and he served out to cement that advantage. From there he continued to hold his serve to seal a memorable victory.