Portugal Colonial - Sinner, Swiatek tested at US Open as Gauff sets up Osaka showdown

Sinner rallied from a set down to beat Denis Shapovalov 5-7, 6-4, 6-3, 6-3 and is trying to become the first man to retain the title in New York since Roger Federer in 2008.

"I was in a very difficult moment today," said Sinner. "The scoreline was a bit against me today, but I just tried to stay there mentally."

World number one Sinner awaits the winner of the evening session match between US 14th seed Tommy Paul and Alexander Bublik, the 23rd seed from Kazakhstan.

"Week two is completely different. It's getting tougher and tougher, also physically and mentally," said Sinner.

To illustrate that point there were three more retirements in the men's draw on Saturday after the injury-induced exit of sixth seed Ben Shelton the day before.

Alex de Minaur, Lorenzo Musetti and 435th-ranked Swiss qualifier Leandro Riedi all moved on when their opponents threw in the towel.

Eighth seed De Minaur led Daniel Altmaier 6-7 (7/9), 6-3, 6-4, 2-0 when the German retired, while 10th seed Musetti held a two-set lead over Flavio Cobolli before the latter packed it in because of an arm injury.

"I didn't want to finish like that, especially against Flavio. He's probably one of my best friends on tour," said Musetti.

Riedi became the lowest-ranked man to reach the fourth round of a major since 2002 as Polish opponent Kamil Majchrzak retired after eight games due to injury.

Unseeded Jaume Munar, 28, also advanced in what is his most successful performance at a Grand Slam but Hong Kong's Coleman Wong saw his brave run ended by a five-set loss to 15th seed Andrey Rublev.

The 21-year-old Wong had become the first player from Hong Kong ever to win a Grand Slam singles match in the Open era.

- Swiatek fights back -

Swiatek showed great resolve to dig herself out of trouble against Russian 29th seed Anna Kalinskaya under the lights of Arthur Ashe Stadium.

The world number two slid 5-1 behind in the opening set but saved four set points and won a tie-break before eventually seeing off Kalinskaya 7-6 (7/2), 6-4.

Swiatek, the 2022 US Open champion and six-time major winner, was far from her best but scrambled through to a last-16 meeting with Ekaterina Alexandrova.

"I felt like I had nothing to lose because I was losing pretty bad. So in the end I just went for it because what else can you do?" Swiatek said of her fightback.

Russian 13th seed Alexandrova has never made it past the fourth round at a Grand Slam but destroyed Laura Siegemund 6-0, 6-1 and has surrendered just 10 games en route to the second week in New York.

Gauff swept past Polish 28th seed Magdalena Frech 6-3, 6-1 in her most polished display of the tournament to boost her hopes of collecting a second US Open title.

After battling to a tearful victory in the previous round, a much more composed Gauff dispatched Frech with relative ease to begin Saturday's action.

"It's been an emotional week, but I think I needed those tough moments to move forward. I was putting so much pressure on myself," said Gauff, through to the last 16 at Flushing Meadows for the fourth year in a row.

"I think today showed I was really having fun out there."

Gauff heads into a showdown on Monday with former world number one Osaka after the Japanese star beat Australian 15th seed Daria Kasatkina 6-0, 4-6, 6-3.

Four-time Grand Slam champion Osaka is enjoying her best US Open showing since winning the tournament for the second time in 2020.

The last-16 match will be a repeat of the duo's first meeting at the US Open in 2019, when Osaka overpowered the then 15-year-old Gauff in straight sets.

"Everyone will be watching. That's what tennis needs," said Venus Williams, who progressed to round three of the the women's doubles on Saturday with partner Leylah Fernandez.

Wimbledon runner-up and eighth seed Amanda Anisimova beat Romania's Jaqueline Cristian 6-4, 4-6, 6-2

Karolina Muchova won an all-Czech encounter with Linda Noskova 6-7 (5/7), 6-4, 6-2. Ukrainian 27th seed Marta Kostyuk overcame France's Diane Parry in three sets.

P.L.Madureira--PC