It was a rematch of the 2009 US Open Final as Juan Martin Del Potro faced Roger Federer on Arthur Ashe Stadium. And 8 years later, Del Potro notched another win against his rival, 7-5, 3-6, 7-6, 6-4.

In the first set, both players had little trouble holding serve while neither showed their top level. But late in the set, it was Del Potro who found another gear. He would break to gain a 6-5 advantage and would promptly close out the set on his racket.

But in the second set, Federer was quick out of the gate, gaining a service break against the big Argentine’s serve. He would sprint to a 4-1 lead as he changed his strategy, attempting to draw the 24-seed in. The change of game plan worked as Del Potro was unable to make inroads into the Federer serve the remainder of the set and the match was evened.

In the third set, some errors crept into Federer's game opening the door for Del Potro. He would quickly capitalize, break serve and open a 4-1 lead. Federer showed signs of frustration in the set as he missed some shots he would normally convert. But the Swiss stuck with it and as Del Potro served up 4-2, he created a break point opportunity which followed with a big “come on.” He obtained the break after Del Potro double-faulted. The set would be decided by a tiebreak.

In the tiebreak, Federer gained an advantage behind tremendous defense as Del Potro popped his big forehand. But as Federer tried to avoid the big Del Potro weapon, the Argentine was still able to find his share to even the tiebreak midway through. However, two missed forehands gave the Swiss two set points. But Del Potro was not deterred as he saved both of those and two more before he took control, winning the tiebreak and set as he took the last three points.

After four easy service holds in the fourth set, Federer wavered and found himself facing two break points, serving at 2-2. The 19-time major champion saved both, but serving at deuce, after solid defense from Del Potro, he dumped an overhead into the net and then saw a return of serve whistle by him for a winner giving the Argentine a break advantage.

After gaining the break, Del Potro held with ease, then serving to close out the match at 5-4, he jumped out to a 30-love advantage. But Federer worked his way back into the game and had a makeable put-away while at the net but struck an errant shot that gave Del Potro match point. He would close it out to advance to the final four. Too many errors down the stretch haunted the 36-year old while Del Potro struck just one unforced error in the fourth set.

“I think I played my best match of the tournament,” Del Potro said afterward. “I did everything well.”

The result eliminated the possibility of a Nadal-Federer semifinal as Del Potro will now take his shot at the world no.1 on Friday. Nadal defeated Andrey Rublev 6-1, 6-2, 6-2 in the day session at Arthur Ashe Stadium.