The disqualification of Novak Djokovic from the US Open, and the absences of Rafael Nadal and Roger Federer, presented quite an opportunity to Alexander Zverev and the other men left in the tournament - all in their 20s, all seeking a first Grand Slam title.
In women's action Tuesday, two-time Grand Slam champion Naomi Osaka set up a semifinal against 28th-seeded Jennifer Brady, a 25-year-old from Pennsylvania who's never been this far at a major tournament.
Naomi Osaka sets ups Jennifer Brady semi-final
Osaka, the former No. 1-ranked played who won the U.S. Open two years ago, played far cleaner tennis than her opponent in a 6-3, 6-4 win over 93rd-ranked Shelby Rogers at night.
Rogers finished with 27 unforced errors, Osaka with eight.
Earlier, Brady defeated No. 23 seed Yulia Putintseva of Kazakhstan 6-3, 6-2.
Done in by double-faults and bothered by an officiating decision, Zverev stumbled at the start of Tuesday's quarterfinal against Borna Coric. Then, suddenly, Zverev soared.
Down a set and a break early, then so close to trailing by two sets to one, Zverev grabbed 14 of 15 points in a pivotal stretch on the way to earning his first semifinal berth at Flushing Meadows with a 1-6, 7-6 (5), 7-6 (1), 6-3 victory over Coric.
"The Novak news shocked us all," Zverev said, "and obviously for us younger guys, we see that as a massive opportunity. But we have to put our head down and do our job."
"I felt like I was in charge of the match. I saw he was struggling, not playing his best tennis," said the 27th-seeded Coric.
"I don't want to stop here," the 6-foot-6 Zverev said.
It was Carreño Busta who was the beneficiary when Djokovic was defaulted from their fourth-round match for hitting a ball that accidentally hit a line judge in the throat after a game.
The men's quarterfinals Wednesday: Dominic Thiem vs. Alex de Minaur, and Daniil Medvedev vs. Andrey Rublev.
Wednesday's women's quarterfinals are Serena Williams vs Tsvetana Pironkova, and Victoria Azarenka vs. Elise Mertens.
Returning to the US Open semifinals for the first time since 2018, when Osaka her maiden Grand Slam title, Naomi Osaka outslugged unseeded American Shelby Rogers, 6-3, 6-4, on Tuesday night under the lights in Arthur Ashe Stadium.
It marked a reversal of fortune for the 4th-seeded Japanese superstar, who had come up short in three previous encounters with Rogers without winning a single set.
Osaka, 22, who two years ago became the youngest champion in Flushing Meadows since Maria Sharapova in 2006, was on her game from the start. She smacked five aces in the 38-minute opening set, and dropped just nine points on her serve. Ahead 4-3, she broke the 93rd-ranked Rogers at love, punctuated by a crosscourt forehand winner.
Alexander Zverev recovered from a set down to win a nervy, sweaty three-hour battle with Borna Coric, 1-6, 7-6, 7-6, 6-3, to advance to the semifinals of the 2020 US Open.
Instead, this turned out to be a battle of nerves. (And sweat, as Coric had to change his drenched clothes on multiple changeovers, much to the consternation of his opponent.) The first set was over quickly. The German, who can be vulnerable on serve, threw in three double faults on his second service game to hand the break to Coric. From there, the No. 5 seed unraveled and couldn't seem to connect on any shot—not even his generally solid backhand—and the Croatian player quickly reeled off the next four games to take the set in 24 minutes.