PARIS -- Rafael Nadal was locked in a tight, compelling and lengthy French Open semifinal Friday when his opponent, third-seeded Alexander Zverev, ran to to chase a shot and twisted his right ankle. Zverev crumpled to the ground, wailing in agony and clutching at his lower leg.
His black outfit, arms and legs caked with rust-colored clay, Zverev was helped up by a trainer, then taken away from the court in a wheelchair. Minutes later, after Nadal saw him crying in a small room in the stadium, Zverev came back out onto Court Philippe Chatrier on crutches, his right shoe removed, and conceded the match, unable to continue.
The sudden end to a contest that was 3 hours old but not even through two full sets allowed Nadal to become, on his 36th birthday, the second-oldest men's finalist in French Open history. Now he will try to become the oldest champion at a tournament he's already won a record 13 times, facing first-time Grand Slam finalist Casper Ruud on Sunday.
"Only thing that I can say is I hope he's not too bad. Hopefully it's just the normal thing when you turn your ankle, and hopefully nothing (is broken). That's what everybody hopes," Nadal said. "Even if for me it's a dream to be in the final of Roland Garros, of course that way is not the way that we want it to be. ... If you are human, you should feel very sorry for a colleague."
With the pitter-patter of rain audible against the closed retractable roof at Court Philippe Chatrier, and many in the crowd of 15,000 repeatedly chanting "Ra-fa! Ra-fa!" he emerged to claim a tight-as-can-be, draining first set by a 7-6 (8) score after 1 1/2 hours. The second set also was headed to a tiebreaker after another 1 1/2 hours when Zverev tumbled behind the baseline and lost a point that allowed Nadal to hold serve for 6-all.
A trainer came out to attend to him, and Nadal walked around the net to check on Zverev, too. After Zverev returned to the court to say he would need to retire from the match, he shook the chair umpire's hand and then hugged Nadal.
Nadal has been dealing with chronic pain in his left foot and was coming off a pair of victories that each lasted more than 4 hours - including his quarterfinal against defending champion Novak Djokovic that ended at 1:15 a.m. on Wednesday - but showed no signs of age, injury or fatigue against the 25-year-old Zverev.
What Nadal said afterward did give him trouble was the way the heavy humidity affected things, with clay sticking to the tennis balls and making it harder for him to apply his thick topspin.
"The conditions were not the ideal for me this afternoon - or the way that I like to play, normally, here," Nadal said. "That's why I was not able to create the damage that I wanted."
In addition to bidding for a 14th trophy from the French Open, Nadal can claim his 22nd Grand Slam title to add to the men's record he already holds after his triumph at the Australian Open in January. Djokovic and Roger Federer are tied at 20.
There's also this on the line for Nadal in Sunday's final against Ruud: It would be the first time the Spaniard ever has won the first two legs of the calendar-year Grand Slam.
Ruud became the first man from Norway to reach a major final, eliminating 2014 U.S. Open champion Marin Cilic 3-6, 6-4, 6-2, 6-2 in a match interrupted for more than 10 minutes in the third set by a climate activist who attached herself to the net and knelt on the court.
The 23-year-old Ruud never has faced Nadal but trained at the King of Clay's academy in Mallorca.
"He's a perfect example of how you should behave on court: Never give up and never complain. He's been my idol for all my life," said Ruud, who his coached by his father, Christian, a pro player from 1991-2001. "I guess this is perfect timing and worth the wait to finally play him in a Grand Slam final."
Zverev was the runner-up at the U.S. Open two years ago and won a gold medal at the Tokyo Olympics last summer, but is still seeking his first major title.
"He was very unlucky," Nadal said. "The only thing that I am sure is he is going to win not one - much more than one. So I wish him all the best and a very fast recovery."
Zverev compiled nearly twice as many winners, 40-21, and got off to an "amazing" start, according to Nadal, who called it "a miracle" that he took the first set.
Zverev led 4-2 in each set.
But in the first, his racket flew out of his hand and landed behind him after one wild swing mistakenly sent a ball zipping past the chair umpire until it landed 10 feet wide of the court. Later, an errant backhand let Nadal break for the first time, making it 4-all and sending red-and-yellow Spanish flags flapping in the stands.
In the opening tiebreaker, Zverev led 6-2, for four set points. But Nadal erased them all, including one by sprinting to his left, ending up wide of the doubles alley, to somehow conjure up a cross-court forehand passing winner at an unbelievable angle. The crowd gave him a standing ovation. He probably had no business getting to Zverev's sharp volley, let alone fashioning that short of response.
And yet, that is what Nadal does, so often, to so many opponents. He hangs in there, he never takes a point off, he plays each shot as if it might be his very last.
Been that way since he was a teen. Why stop now that he's in his mid-30s?
The only older men's finalist in Paris was Bill Tilden, the runner-up at 37 in 1930. The oldest champion so far was Andres Gimeno, who was 34 in 1972.
Nadal, who first won the championship at Roland Garros on his debut at age 19, has said in recent days that he can't be sure whether each match might be his last at the French Open. His left foot is the primary reason for that pessimism.
"All the sacrifices, and all the things that I need to go through to try to keep playing," Nadal said, "really make sense when you enjoy moments like I'm enjoying in this tournament."