NEW YORK - Reigning men's champion Jannik Sinner charged into the third round of the US Open on Thursday as Coco Gauff and Iga Swiatek battled to keep their title bids intact.
Sinner swatted Australia's Alexei Popyrin aside 6-3, 6-2, 6-2 to stretch his Grand Slam winning streak on hard courts to 23 matches.
The Italian top seed has made a convincing start in his bid to become the first man to repeat as US Open champion since Roger Federer won five in a row from 2004-2008.
Sinner faces Canadian 27th seed Denis Shapovalov in the third round on Saturday.
He has reached the final of all three Grand Slams this season, winning the Australian Open and Wimbledon either side of a defeat to Carlos Alcaraz at the French Open.
Gauff displayed great resolve to overcome another shaky performance that reduced her to tears in the night session on Arthur Ashe.
Third seed Gauff shrugged off Croatia's Donna Vekic 7-6 (7/5), 6-2 despite being broken four times in the opening set as her serving woes resurfaced.
"Honestly, today was a tough match for me, but I'm just happy with how I was able to manage it," said Gauff, choking back tears. "It's been a rough couple of weeks."
"I was just trying to tell myself to breathe, just put another ball in the court and keep doing the things that I do well," she added.
Swiatek started Thursday's action on Arthur Ashe by fending off the Netherlands' Suzan Lamens 6-1, 4-6, 6-4.
World number two Swiatek looked to be cruising as she led by a set and a break but stumbled before eventually seeing off the 66th-ranked Lamens.
Swiatek, the 2022 US Open champion, has won 16 of 17 matches following titles at Wimbledon and Cincinnati. She faces Russian 29th seed Anna Kalinskaya for a spot in the last 16.