Novak Djokovic used his experience to overcome American Ben Shelton as the Serbian battled past his 20-year-old challenger 6-3 6-2 7-6(4) to reach his 10th U.S. Open final on Arthur Ashe Stadium on Friday.
Shelton had flummoxed opponents in New York with his big serve but the 36-year-old second seed Djokovic was able to harness his experience to neutralise a third-set surge from the young American.
He next faces the winner of a match between top seed and defending champion Carlos Alcaraz and third seed Daniil Medvedev.
"These are the kind of matches and occasions that I still thrive on, that still get me going," Djokovic said on court. "Trying to work as hard as the young guys."
Already assured of returning to the top of the world rankings when they are updated after the tournament, Djokovic will continue the hunt for his 24th Grand Slam title to match Margaret Court's all-time singles record on Sunday.
Shelton handed Djokovic a break in the sixth game of the first set with a series of unforced errors, and the unseeded American was unable to convert his own break point chance in the ninth.
In the second set, Shelton's best weapon failed him as he helped Djokovic secure a break with a double fault in the fifth game and he dropped his racquet in frustration as he sent a forehand out to hand the Serb another break in the seventh.
Djokovic was competing in his 47th major semi-final while Shelton was appearing in his first and the difference in experience was apparent as the second seed broke Shelton with a fine forehand winner in the opening game of the third set.
But the American came to life late as he fended off a break point with a 143mph ace in the fifth game to a chorus of cheers from the home crowd.
Playing in only his seventh U.S. Open singles match, Shelton triumphed in a 30-shot rally before converting a break point in the eighth game, humbling Djokovic, who was appearing in his 100th singles match at the hardcourt major.
Djokovic broke again in the 11th game but could not stop the set from going into a tiebreak as he swatted one into the net to allow Shelton to break back in the 12th game.
The Serb forced Shelton into a forehand error on match point and made a not-so-subtle jab at the American's favoured celebration as he mimed hanging up the telephone while walking to the net.
"Got to hold the nerves and try to be composed in the moment," said Djokovic. "It was really anybodyG��s game (at the end) of the third set."
Women's semi-finals
On Friday, second seed Aryna Sabalenka staged a Grand Slam fight back for the ages to rock Madison Keys 0-6 7-6(1) 7-6(5) and deny the home crowd the all-American women's final.
Sabalenka will now try to heap even more disappointment on U.S. tennis fans in Saturday's final when she takes on Coco Gauff, who beat Karolina Muchova 6-4 7-5 in a match halted for nearly an hour when an environmental activist glued his feet to the floor of Arthur Ashe Stadium.
"I don't know actually how I turned around this match," said Sabalenka. "I won it and it really means a lot being in the final of the U.S. Open for the first time.
"It was really incredible match, she played unbelievable tennis.
"I'm really proud of myself that I was able to turn around this game and get this win, because it was just incredible."
A giddy capacity crowd waving U.S. flags were ready to celebrate getting the final they hoped for when Keys bageled the Belarusian in the opening set and was 5-3 up in the second, serving for a spot in the final.
But Sabalenka had other ideas.
Her fight back began by breaking Keys to get back to 5-4 and continuing the match. It would end two tie-breaks later with the Belarusian walking off court into her second Grand Slam final of the season.
"I was all over the place," said Sabalenka. "I was just, like, what can I do? She's playing unbelievable, just, like, crushing everything.
"I'm not able to do anything, I had zero control in the match.
"I was just kept telling myself, okay, you just have to keep trying, keep staying there, and keep pushing it.
"Maybe you'll be able to turn around this game.
"Lucky me, somehow magically, I don't know how I was able to turn around this game."
In a contest featuring two of the biggest hitters in the women's game, it was Keys coming out all guns blazing to dominate the Belarusian, who will take over as world number one when the rankings are updated on Monday.
Soaking up the energy of the home crowd, the 17th seed unleashed a barrage of winners and broke Sabalenka three times to open the match 6-0.
Keys broke the Australian Open champion for a fourth time for a 2-1 lead in the second, leaving a frustrated Sabalenka screaming and smashing her racquet.
But with Keys serving for a place in the final the Sabalenka who players fear finally appeared.
The Belarusian got her first break of match as the set went to a tie-break which she won 7-1, sending the contest to a third set that minutes earlier no one saw coming.
With the tension rising so did the quality of the match, the players trading breaks in a tight third set that came down to a super tie-breaker which Sabalenka again dominated 10-5.
- Reuters