NEW YORK - With no players from the United States left to pull for in the US Open, the fans are adopting a neighbor from the North to treat as one of their own: Leylah Fernandez, an unseeded Canadian teenager with an exciting game and enthusiasm to match.

A day after turning 19, Fernandez reached her first Grand Slam semifinal — and became the youngest player to get that far in the women's bracket at Flushing Meadows since Maria Sharapova in 2005 — by adding a 6-3, 3-6, 7-6 (5) victory against No. 5 Elina Svitolina on Tuesday to earlier wins over past US Open champions Naomi Osaka and Angelique Kerber.

"I obviously have no idea what I'm feeling right now," said Fernandez, a left-hander with quick baseline reflexes who is ranked 73rd and participating in only the seventh major tournament of her nascent career. "I was so nervous. I was trying to do what my coach told me to do." That coach is her father, who isn't in New York; he stayed home and is offering tips in daily phone conversations. That helps, certainly, as does the loud backing she's been receiving from the spectators, who rose and cheered wildly each time Fernandez raised a fist high above her head or wind-milled both arms after winning a key point in Arthur Ashe Stadium.

"Thanks to you, I was able to push through today," she told the crowd after edging Svitolina, the Tokyo Olympics bronze medalist whose two Grand Slam semifinal runs include at the 2019 US Open.

Not requiting any encouragement to get out of his seat was Fernandez's fitness coach, who would leap and shout, pointing fingers or waving clenched fists. Svitolina's husband, two-time major semifinalist Gael Monfils, offered similar support from Ashe's other guest box. It was touch-and-go down the stretch — even after Fernandez grabbed the opening set, even after she led 5-2 in the third. One way in which she held a clear advantage: Of points that lasted more than eight shots, Fernandez won 26, Svitolina 16.

Five times, Fernandez was two points from winning but failed to collect the next point. Finally, at 5-all in the tiebreaker, she moved to match point when she smacked a down-the-line passing shot that got past Svitolina with the help of a bounce off the net tape. Fernandez put up both palms, as if to say, "Sorry about that bit of luck," while Svitolina put a hand to her mouth in dismay.

Svitolina's backhand contributed to her undoing late, and when a return from that side landed long, it was over. Fernandez dropped to her knees at the baseline and covered her face; Svitolina walked around the net to come over for a hug.

Next on this magical ride for Fernandez will come yet another test against a player who is ranked higher and has more experience success on the sport's biggest stages. On Thursday, she will play either No. 2 Aryna Sabalenka, who reached the Wimbledon semifinals in July, or No. 8 Barbora Krejcikova, who won the French Open in June and was the only woman in the round of eight at the US Open with a Grand Slam title.

Sabalenka and Krejcikova's night match was to be followed by the men's quarterfinal between another young Canadian, 21-year-old Felix Auger-Aliassime, and 18-year-old Carlos Alcaraz of Spain. The winner of that will face No. 2 seed Daniil Medvedev in the semifinals.

Medvedev, a 25-year-old from Russia, earned a spot in the final four at Flushing Meadows for the third consecutive year by stopping the surprising run of Dutch qualifier Botic van de Zandschulp 6-3, 6-0, 4-6, 7-5.

As in the women's draw, only one man in the quarterfinals already owns a major trophy: Novak Djokovic, who not only is seeking a record-breaking 21st but also trying to become the first man since Rod Laver in 1969 to win a calendar-year Grand Slam.

Medvedev has come close. He lost to Djokovic in this year's Australian Open final and to Rafael Nadal in the 2019 US Open final.

The only way he could meet Djokovic this time would be in the title match on Sunday. But first things first.

"I don't think about him, because as we saw, anybody can beat anybody," Medvedev said. "If he's in the final, and if I'm there, I'm happy. He's also happy, I guess."