Sinner starts title defence, Swiatek and Gauff in action

NEW YORK :The U.S. Open's first round continues on Tuesday, with men's top seed Jannik Sinner beginning his title defence, while Iga Swiatek and Coco Gauff launch their bids to dethrone women's defending champion Aryna Sabalenka.

TOP MEN'S MATCH: JANNIK SINNER V VIT KOPRIVA

It has been over 13 months since a men's Grand Slam final took place without Jannik Sinner. The Italian has since won three out of four majors, and is favourite to defend his title at Flushing Meadows.

The 24-year-old's rivalry with world number two Carlos Alcaraz, who he faced in the last two slam finals, is now a major storyline in the game.

In last week's Cincinnati Open final they met again, and an uncomfortable Sinner retired due to illness after 23 minutes trailing 5-0.

Sinner said on Friday he was fit for the U.S. Open, but his health is still a concern ahead of the world number one's first-round clash with Kopriva.

"At the moment, me and Carlos, we are sharing big trophies, but at the same time, things can change... you never know," Sinner told reporters.

"There are great, great players out there... the way to the final, it's very difficult to get there."

TOP WOMEN'S MATCH: EMILIANA ARANGO V IGA SWIATEK

World number two Iga Swiatek has had a good year despite failing to win a fourth straight French Open title, reaching the two Grand Slams semi-finals before winning Wimbledon to add a sixth major to her trophy cabinet.

The 24-year-old Pole won the Cincinnati Open and although known as the "Queen of Clay" for her dominance at Roland Garros, most of Swiatek's WTA titles have been won on hard courts.

"For sure, I feel really a positive vibe after this tournament, because in Cincinnati I feel like my tennis really progressed match by match," Swiatek said.

"Ho