Emma Raducanu celebrates after defeating Belinda Bencic in the quarterfinals of the U.S. Open on Wednesday in New York. Elise Amendola/Associated Press

NEW YORK — When Emma Raducanu got to Flushing Meadows to try to win her way through qualifying and earn what would be a berth in her second Grand Slam tournament, she was not planning on a particularly long stay.

Look at her now, two weeks into this adventure: The 18-year-old from Britain is the first qualifier in the professional era to reach the U.S. Open semifinals. And she hasn’t even dropped a set yet.

“My flights were booked at the end of qualifying,” Raducanu said with a chuckle Wednesday, “so it’s a nice problem to have.”

Showing off the shots and poise of someone much more experienced, the 150th-ranked Raducanu became the second unseeded teen in two days to secure a spot in the final four, eliminating Tokyo Olympics gold medalist Belinda Bencic 6-3, 6-4 in Arthur Ashe Stadium.

Not bad for someone ranked outside the top 350 in June after going about 1 1/2 years without a match – in part because of the coronavirus pandemic, in part because her parents wanted her to finish high school.

“I’m not here to chase any records right now,” said Raducanu, only the third woman not ranked in the top 100 to make it this far at the U.S. Open and only the fourth qualifier to advance to the semifinals at any major tournament since the Open era began in 1968. “I’m just taking care of what I can do (in) the moment.”

Raducanu has won all 16 sets she has contested through eight matches in New York – three during the qualifying rounds and another five in the main draw. She will play again Thursday against No. 17 seed Maria Sakkari of Greece, a semifinalist at this year’s French Open. Sakkari won 6-4, 6-4 against No. 4 seed Karolina Pliskova, the 2016 U.S. Open runner-up.

The other women’s semifinal will be 19-year-old Leylah Fernandez of Canada against No. 2 seed Aryna Sabalenka of Belarus.

In the men’s quarterfinals Wednesday, Olympic champion and 2020 U.S. Open runner-up Alexander Zverev stretched his winning streak to 16 matches with a 7-6 (6), 6-3, 6-4 victory over unseeded Lloyd Harris.

Harris went up 5-3 in the opening set but got broken while serving for it. He then held a set point at 6-5 in the tiebreaker but couldn’t convert, and the fourth-seeded Zverev was on his way. The 24-year-old from Germany grabbed the next three points for that set, then moved out to leads of 3-0 in the second and 4-0 in the third.

“Somehow managed to win that first set,” Zverev said. “Loosened me up a little bit.”

Shortly after he lost to Dominic Thiem in last year’s final at Flushing Meadows, Zverev was accused by a former girlfriend of domestic abuse, allegations he repeatedly has denied.

His second consecutive U.S. Open semifinal will come against No. 1 Novak Djokovic, who is bidding for a calendar-year Grand Slam, or No. 6 Matteo Berrettini. Their quarterfinal, a rematch of the Wimbledon final won by Djokovic in July, was scheduled for Wednesday night.

“I am going to watch it, like everybody else, I guess,” Zverev said. “I hope it goes for 8 hours and 30 minutes.”

Raducanu made her Grand Slam debut at Wimbledon thanks to a wild-card invitation, and she made it to the fourth round before stopping during that match when she had trouble breathing.

That tournament allowed the world to begin to get familiar with her style of crisp, clean tennis, managing to attack early in points from the baseline without sacrificing accuracy. By the end against the 11th-seeded Bencic, a U.S. Open semifinalist in 2019, Raducanu had nearly twice as many winners as unforced errors, 23-12.

She also showed gumption, both at the beginning, when she was undaunted by a 3-1 deficit and claimed the next five games, and at the end, when she fell behind love-30 each of the last two times she served before hanging on.

“Obviously she’s very solid,” said Bencic, who hadn’t dropped a set before Wednesday, “to just kind of stay tough till the end and just play her game and kind of not let me in again.”

When Bencic double-faulted to get broken and fall behind 3-2 in the second set, she trudged, slow as can be, to a corner of the court to retrieve her towel. When she got to her sideline seat, she whacked her racket against her equipment bag, then plopped herself down and smacked the racket against the ground.

Raducanu jogged to the sideline, showered in applause and cheers from the crowd.

Just like the prior afternoon, the Ashe spectators lent their considerable support to a teenager whose name is not yet well-known and who’s not yet all that accustomed to gracing these stages.

On Tuesday, a day after turning 19 and sharing cupcakes with Raducanu and others in the locker room, it was Fernandez who got past No. 5 seed Elina Svitolina 6-3, 3-6, 7-6 (5) to become the youngest semifinalist at Flushing Meadows since Maria Sharapova in 2005.

On Wednesday, it was the even-younger Raducanu’s turn.

Her father is Romanian, her mother is Chinese, and Raducanu was born in Toronto, before the family moved to England when Emma was 2.

Mom and Dad did not make the trip to New York – and they’re not exactly in constant contact with their precocious daughter.

“I haven’t actually called my parents for quite a while,” Raducanu said with a sheepish smile and a roll of her eyes. “Yesterday, like the day before, they were ghosting me.”