Youth ruled tennis on Friday in Shanghai, where Stefanos Tsitsipas upset No. 1 Novak Djokovic and Alexander Zverev beat his new mentor, Roger Federer.
It also ruled a continent away in Linz, Austria, where the 15-year-old Coco Gauff added another exclamation point to her breakthrough season by defeating top-seeded Kiki Bertens, 7-6 (1), 6-4, to reach her first WTA tour singles semifinal.
“It’s my biggest win, ever,” said Gauff, sounding like a veteran surveying a long career instead of a teenager who has yet to play a full year on tour.
Her run to the fourth round at Wimbledon, in her Grand Slam singles debut this summer, certainly made a deeper impression; the Linz Open is not even being televised in the United States.
But in statistical terms, this was no doubt Gauff’s most impressive victory. Until Friday, she had never beaten a top-40 player. Bertens, a powerful 27-year-old from the Netherlands, is No. 8.
The victory made Gauff the youngest player to reach the semifinals of a WTA tournament since 2004. More important for her longer-term goals, she is guaranteed to break into the top 100 on Monday and has thus secured a spot in the Australian Open, the next Grand Slam tournament. Gauff will be the only player under 18 in the top 100.
“In some corner of her mind, there was some pressure to do really well here to be able to be sure to be in the main draw in Australia,” Jean-Christophe Faurel, one of her coaches, said in an interview from Linz.
Faurel said that helped explain why the week did not start auspiciously: Gauff, who is restricted to a limited number of pro tournaments because of her age, lost in the second round of the qualifying event in Linz.
But she still found a way into the main tournament — as a “lucky loser” when other players withdrew. As she has done repeatedly since qualifying for Wimbledon, Gauff pounced on the opportunity to get the better of her elders.
She never lost her serve against Bertens.
“Today was really impressive from start to finish, and it needed to be,” Faurel said.
Gauff’s semifinal opponent on Saturday will be Andrea Petkovic of Germany, who is ranked No. 75.
It will be another clash of the generations: Petkovic, 32, is more than twice Gauff’s age. Such duels have been a hallmark of the 2019 tennis season, with Bianca Andreescu, a 19-year-old from Canada, defeating Serena Williams, then 37, in the final of the United States Open last month.
In the men’s game, the elders have continued to hoard the major trophies, with Djokovic, 32, and Rafael Nadal, 33, each winning two of the four Grand Slam titles this year.
The so-called Big Three of Djokovic, Nadal and Federer remain in the top three spots in the rankings.
But signs of insurrection are increasing, particularly in best-of-three-set events. The old guard got locked out of the semifinals at the Shanghai Masters, where Zverev will face Matteo Berrettini, and Tsitsipas will face Daniil Medvedev, the Russian who pushed Nadal to a fifth set before losing their grueling, gripping U.S. Open final last month.
Medvedev and Berrettini are 23. Zverev is 22, and Tsitsipas is 21.
This is the first time since Hamburg in 1999 that four players younger than 24 have reached the final four of a Masters Series event.
Tsitsipas, who defeated Djokovic, 3-6, 7-5, 6-3 on Friday, has beaten each member of the Big Three this season.
“They’re knocking on the door big time, the young guys,” said Federer, 38, who has now lost four of his seven matches against Zverev.
They have spent plenty of time together of late. Earlier this season, Zverev signed with Team8, the agency that Federer started with his agent, Tony Godsick.
Last month in Geneva, Federer and Zverev were teammates again in the Laver Cup. Zverev clinched Team Europe’s victory with a win over Milos Raonic after getting a profane and effective pep talk from Federer during an off-court break.
Federer stressed the importance of staying positive under duress and told Zverev he could turn his downbeat season around.
So far so good for Zverev, whose big serve is back to being reliable and who shrugged off the loss of five match points in the second set on Friday, then closed out the victory in the third, 6-3, 6-7 (7), 6-3.
But Federer, despite an extraordinary passage of play late in the second set, was far from the portrait of positivity himself. He hit a ball into the stands in frustration, receiving a warning for ball abuse, and then got a very rare point penalty for a second code violation in the third set, when he hit another ball into the stands after missing a backhand half volley.
“Next question,” Federer said later about the incident.
Along the mood-swinging way, he had several extended discussions on court with the chair umpire, Nacho Forcadell Gil.
But the last word was left to Zverev. “It’s my time,” he screamed after winning the sixth match point.
We’ll see how long his time lasts, but there was no doubt that Friday belonged to the sport’s youth.