But only one of them will get to play in the U.S. Open final on Saturday, quite possibly against Serena Williams, the 37-year-old American icon, who will face a tough test of her own against No. 5 seed Elina Svitolina in Thursday night’s first semifinal.

“At this point, I think anyone can win the tournament; the other semifinalists are incredible athletes,” Andreescu said. “Hopefully I can do good things tomorrow.”

Bencic certainly has the skills to disrupt Andreescu’s game, just as she disrupted the defending champion and No. 1 seed Naomi Osaka’s game in the fourth round, beating her for the third time this season.

“I practiced with her once in Toronto,” Andreescu said of her recent session with Bencic. “I found that she takes the ball really early. She likes to be very aggressive. She has a very good serve and she moves pretty well, too. So I’m going to do my best to just focus on myself mainly and just keep doing what I’m doing because I think my game is throwing off a lot of players.”

Andreescu is 7-0 against top 10 players this season and 13-3 in three-set matches. Ranked No. 178 at the end of last season, she is about to break into the top 10 and has not lost a completed match since March. That statistic is misleading because she missed significant playing time with a rotator cuff injury, including most of the clay-court season and all of the grass-court season.

She is on quite a roll again after winning the Rogers Cup in Toronto, her hometown. She prevailed in the final after Williams retired with a back injury when trailing by 3-1.

Andreescu’s form has fluctuated in New York, particularly in her last two matches, both played in the cavernous confines of Arthur Ashe Stadium.

