Juan Martin del Potro reached the final of the US Open on Friday after the defending champion and number one in the world, Rafael Nadal, retired from his last match with a knee injury. Third seed Del Potro, the champion in 2009, was 7-6 (7/3), 6-2 ahead when Nadal retired. The Argentine will face Novak Djokovic, the winner of 2011 and 2015 in the final on Sunday. "I hate to retire," said Nadal, who suffered a series of knee injuries throughout his career. He also retired in the fifth set of his Australian Open quarterfinal match against Marin Cilic in January.
"It's not a match when one is playing and the other is on the side of the court."
Nadal, who was looking for his fourth title in New York and 18th major, had spent the best part of the 16 hours to reach the semifinals.
That effort made a dent and the Spaniard needed twice to bandage his right knee before calling it a day after the conclusion of the second set.
"Well, of course it's not the best way to win a game, I love playing against Rafa because he's the biggest fighter in the sport and I do not like to see him suffer," said Del Potro, 29, who will. be playing in his second Slam final.
"I'm sad for him, but I'm also happy to do my best."
Nadal's challenge seemed condemned even from the first set, feeling the injury after only four games, he admitted.
He needed his right knee tied after the seventh game before gallantly fighting a two-point set in the 10th game, breaking Del Potro serving for the whole.
But the great Argentine swept the tiebreaker, finishing the first game after 69 minutes of impressive shooting.
The Spaniard asked for a medical waiting time after three games of the second set to avenge his right knee.
Del Potro felt blood and broke 3-1 while Nadal struggled to move.
He broke again 5-2 on his way to a two-set lead and an eventual victory.
"It means a lot to be back in the final," Del Potro added after his sixth victory over Nadal, all in hard court.
"I did not expect to reach another Grand Slam final in my favorite tournament.
"I had my best memories on this court in 2009 when I beat Rafa and Roger (Federer, in the final.) I was a kid then, now I'm much older."