Federer wiped away a 0-3 deficit in the third set and then won the first three points in the tiebreaker. But del Potro saved four set points before he finally won that set with a mini break. In the fourth set, del Potro got an early break and held off Federer from there, finishing the victory with an emphatic forehand down the line.
This is the second time del Potro has stood in the way of a Federer-Nadal matchup at the U.S. Open. He also did it in 2009 when he beat Nadal in a semifinal and Federer in a five-set final that ended with del Potro, then only 20, lying on his back in a combination of ecstasy and disbelief.
There was some disbelief on Wednesday as well. He was asked in the postmatch interview how he had managed to come out on top in the taut third-set tiebreaker.
“I think I got lucky,” del Potro said. “I made a double fault at 6-6 and you can’t do that against Federer.”
Madison Keys Completes All-American Semifinals
Madison Keys brushed past Kaia Kanepi and completed a sweep.
Keys, who won 6-3, 6-3 over Kanepi on Wednesday night in Arthur Ashe Stadium, became the fourth American woman in the final four of this year’s United States Open, ensuring an American champion already.
Sloane Stephens will face Venus Williams in the first of Thursday’s semifinals, and Keys will face CoCo Vandeweghe in the second.
It is the first time the United States (or any country) has claimed all four semifinalists at a women’s Grand Slam event since Wimbledon in 1985, when Martina Navratilova, Chris Evert, Zina Garrison and Kathy Rinaldi were the last four.
The last time it happened in New York was in 1981, when Navratilova, Evert, Tracy Austin and Barbara Potter reached the semifinals.
It has been a stellar year for American women’s tennis, even with the country’s best player, Serena Williams, going on maternity leave after winning the Australian Open in January. Venus Williams made the finals of both the Australian Open and Wimbledon.
Vandeweghe made her first major semifinal at the Australian Open. Keys successfully recovered from a second operation on her left wrist to win a tournament in Stanford, beating Vandeweghe in the final. Stephens has won 13 of her last 15 matches, reaching consecutive semifinals in Toronto, Cincinnati, and now New York.
The United States team has also reached the Fed Cup final this year for the first time since 2010. They will play against Belarus in a November final in Minsk.
Whoever wins the U.S. Open will be the first American woman aside from Serena Williams to win a Grand Slam since 2008, when Venus Williams won her seventh and most recent major title at Wimbledon.
No Americans remain in the men’s tournament. Sam Querrey, the lone quarterfinalist, lost to Kevin Anderson on Tuesday night.
Nadal Cruises Into Semifinals
There was much more suspense after the match than during the match on Wednesday as Rafael Nadal won his quarterfinal against Russian teenager Andrey Rublev, 6-1, 6-2, 6-2 in just 1 hour 36 minutes.
From a very early stage, it was clear that Rublev, a 19-year-old with a lightweight frame, did not have the requisite consistency and staying power to keep pace with Nadal, his childhood idol.
Nadal broke Rublev’s serve seven times, won 92 total points to Rublev’s 53 and was very soon answering questions about whether he and Roger Federer will finally get to play at the United States Open. It is the only Grand Slam tournament where they have yet to face off.
For it to finally transpire, Federer needs to defeat Juan Martin del Potro on Wednesday evening in the final men’s quarterfinal of the tournament.
“It’s something a little bit strange that we never played here, because we played a lot of times in all the important events around the world,” Nadal said in an on-court interview. “Will be much more special if that can happen in a final, but it’s not possible this year. So we’re going to come back and try to make that happen.”
With Federer 36 and Nadal 31, the future remains very uncertain, but if they do finally meet here in New York, it will be not only a duel for a place in the final but a duel for the No. 1 ranking, currently held by Nadal.
It has been a throwback season from the start: Federer beat Nadal in a five-set classic to win the Australian Open in January. But Nadal, who did not have glittering hardcourt results this summer leading into the U.S. Open, has rarely had such a straightforward path to the semifinals in New York.
He did not face a top 50 player in the first five rounds, and though he lost a set to Taro Daniel of Japan in the second round and to Leonardo Mayer of Argentina in the third round, he has now won nine straight sets and looks physically fresh, which has often not been the case at the U.S. Open during his long career.
This will be his first U.S. Open semifinal since 2013, when he won his second singles title here.
“Well of course this year has been an emotional year,” said the top-seeded Nadal. “I’ve been playing very well I think almost every tournament after some years with some problems in terms of injuries and sometimes without playing that well. So you appreciate it a lot when you come back and play a lot of matches in a row and you win matches and you fight for important titles.”
CoCo Vandeweghe Tops Karolina Pliskova
Even though it was a singles match, there were two winners and one loser on Wednesday afternoon.
CoCo Vandeweghe’s 7-6 (7-4), 6-3 victory over Karolina Pliskova not only put her into her first United States Open semifinal in singles. It also guaranteed that Garbine Muguruza will replace Pliskova as the world’s No. 1 women’s player on Monday.
Muguruza, the reigning Wimbledon champion from Spain, will be the 24th woman to reach No. 1 since the rankings began in 1975, and she will be the fourth woman in little more than a year to occupy the top spot.
It is a time of uncertainty in the women’s game, a time perhaps of transition with Serena Williams, long the dominant player and personality, now on maternity leave and aiming to come back next season.
But even in Williams’s absence, the Americans are thriving like rarely before at this year’s U.S. Open. Three Americans have now reached the semifinals: Venus Williams, Sloane Stephens and Vandeweghe.
A fourth may soon join them with Madison Keys set to face Kaia Kanepi of Estonia in the final quarterfinal on Wednesday night.
“Let’s make it four for four,” Vandeweghe said, hands on her hips, in her post-match interview.
It has been 36 years since four American women reached the semifinals at the U.S. Open. In 1981, Tracy Austin, Martina Navratilova, Chris Evert and Barbara Potter comprised the final four, with Austin going on to defeat Navratilova in a taut final, 1-6, 7-6 (7-4), 7-6 (7-1).
Tiebreakers have been the key to success for this generation of Americans as well. Venus Williams and Stephens, who will face each other on Thursday, both won their quarterfinals in third-set tiebreakers. And Vandeweghe took control of her quarterfinal with Pliskova by winning the opening-set tiebreaker after saving a set point earlier in the 10th game.
It was an uneven match, full of big serves and unexpected errors under a closed roof in Arthur Ashe Stadium. Both women cracked rackets in frustration, but Vandeweghe has improved her ability to manage her emotions on big occasions this year.
It has been a breakthrough season even if it has included pronounced dips in form and a coaching change: Craig Kardon resigned in the spring and has been replaced by the former Wimbledon men’s champion Pat Cash.
But there is no quibbling with Vandeweghe’s results in the Grand Slam tournaments. She reached the semifinals of the Australian Open, the quarterfinals at Wimbledon and has now advanced to the semifinals here in the same place where she won the girls title at age 16.
“It is a process,” said Vandeweghe, now 25, in her post-match interview. “I did expect it overnight when I was 16, but it is a process and now here I am and I couldn’t wish for anything better.”