San Francisco Frontiers - Rybakina, Gauff advance as Zverev launches US Open campaign

Rybakina, eyeing a third Grand Slam title and the world number one ranking, beat US teen Thea Frodin 6-3, 6-2.

Gauff showed off her immensely improved serve in a confident 6-3, 6-4 victory over 53rd-ranked Zeynep Sonmez of Turkey.

Gauff blazed through the opening set before Sonmez upped her game, recovering an early break in the second and briefly taking the lead before Gauff regrouped.

"I think I was just trying not to panic," Gauff said. "She started coming to the net and playing great tennis.

"That 3-all game was real important," added Gauff, who saved three break points in the sixth game and broke in the next for a lead she wouldn't relinquish.

World number two Rybakina and fourth-ranked Gauff are two of the three players, along with No. 3 Jessica Pegula, who have a chance to supplant Aryna Sabalenka atop the world rankings in New York.

Gauff would have to add a second US Open title to the one she captured in 2023 while Kazakhstan's Rybakina could do it just by reaching the semi-finals.

Kazakhstan's Rybakina showed little sign of the left heel injury that forced her out of her quarter-final in Cincinnati this month.

She saved both break points she faced in a polished performance against the big-hitting if erratic American, who was playing her first Grand Slam main draw match on a wild card.

"I'm happy with the match. Especially when you don't know your opponent, it always can be dangerous, but overall I'm happy with the first match and how it went," the world number two from Kazakhstan said.

"It's a great result after 10 days from that kind of injury," added Rybakina, who was unable to walk without pain for several days and is still carefully managing her training, rest and treatment.

Zverev, who nabbed his long awaited first Grand Slam title at the French Open this year, opened his bid for another against Lorenzo Sonego in the nightcap on Ashe.

Women's French Open champion Mirra Andreeva also advanced easily, cruising past Indonesia's 36th-ranked Janice Tjen 6-2, 6-2.

Andreeva, seeded fifth, has had a lackluster run on North American hard courts since her scintillating run to a first Grand Slam title in Paris.

But she was dialed in as she produced her second win over Tien in less than two weeks.

After a tough win against the Indonesian in Cincinnati, Andreeva said, "I was just trying to be very aggressive."

- Cobolli comeback -

Fifth-seeded Flavio Cobolli, runner-up to Zverev at Roland Garros, rallied from two sets down for the first time in his career to beat Argentina's Francisco Comesana 3-6, 2-6, 6-3, 6-4, 6-4.

The Italian shook off an erratic start, dropping to his knees and raising his arms in celebration after closing out the four-hour, 13-minute marathon.

"In a Grand Slam it's never done," Cobolli said. "You have to fight to the last point."

Cobolli recouped an early break in the fifth set, breaking back to pull level, breaking again for a 5-4 lead and sealing the triumph in the next game with a blistering forehand volley.

He had been flailing in the first two sets against his 119th-ranked opponent, but he saved all eight break points he faced in the third and dominated in the fourth.

In the time it took Cobolli and Comesana to battle it out on the Louis Armstrong stadium, Americans Madison Keys and Taylor Fritz both posted wins on Arthur Ashe Stadium.

Keys a former Australian Open winner who lost in the first round at Flushing Meadows last year, conquered first-match jitters to beat 19-year-old Russian Alina Korneeva 7-5, 6-4.

Nerves didn't seem to be a problem for ninth-seeded Fritz as he sailed past fellow American Darwin Blanch 6-3, 6-2, 6-4.

While play went as scheduled on the covered Ashe and Armstrong stadiums, those on outside courts -- including Rybakina -- had to wait out some lengthy rain delays.

That included a near four-hour delay to the start of play and more delays in the evening. At least five late matches were postponed altogether.

N.Flores--SFF