NEW YORK (AFP) — Emma Raducanu became only the third defending champion to exit the US Open in the first round on Tuesday while four-time winner Rafael Nadal overcame an early scare against a player ranked 198 in the world.

Raducanu, 19, slumped to a 6-3, 6-3 defeat to veteran French player Alize Cornet who is competing in a record 63rd consecutive Grand Slam.

Nadal saw off Australian wildcard Rinky Hijikata 4-6, 6-2, 6-3, 6-3 to register his 65th career win in New York.

Also going through to a politically-charged clash were three-time runnerup Victoria Azarenka of Belarus and Marta Kostyuk of Ukraine.

Raducanu has struggled in the spotlight of being a Grand Slam winner, failing to get beyond the second round of any of the previous three majors in 2022.

"In a way I'm happy because it's a clean slate. The target will be off my back," the teenager said.

World No. 3 Nadal, who is chasing a 23rd Grand Slam title and third of 2022, arrived at the tournament having played just one match since an abdominal injury forced him to forfeit his Wimbledon semifinal.

He next faces Fabio Fognini, the Italian who famously defeated him from two sets down in the third round in 2015.

"I'm very happy to be here. It's a long time that I played here. I thought that maybe I'd never be back," said 36-year-old Nadal, whose last appearance in New York saw him win the 2019 title.

Two-time champion Naomi Osaka was knocked out in the opening round for the first time in seven visits, losing 7-6 (7/5), 6-3 to Australian Open runnerup Danielle Collins.

Four-time major winner and former world No. 1 Osaka has won just twice on tour since April.

"I tried as hard as I could. I wanted to play without my back being in pain. I only really started serving two days ago," Osaka said.

Thursday's action is likely to be dominated by the clash between former world number one Azarenka and Kostyuk, a vocal critic of the presence of Russian and Belarusian players on tour.

Only last week, Azarenka was axed from an exhibition on the eve of the US Open aimed at raising money for Ukraine.

Kostyuk, 20, said she turned down the chance to play in protest at the presence of Azarenka and the 33-year-old Belarusian was swiftly dumped from the event.

Belarus is a close ally of Russia and has allowed Moscow to use its territory to launch attacks into Ukraine during the ongoing war.

World No. 1 and French Open champion Iga Swiatek eased past Italy's Jasmine Paolini 6-3, 6-0 in just 67 minutes.

Victory was a relief for the 21-year-old Pole who had suffered early losses at warm-up events in Toronto and Cincinatti
Swiatek next faces 2017 champion Sloane Stephens.

Carlos Alcaraz, the 19-year-old world No. 4, was made to sweat by Sebastian Baez, winning the first two sets 7-5, 7-5 before the Argentine retired injured 0-2 down in the third.

As the temperature soared beyond the 30-degree mark, 42-year-old Venus Williams and Wimbledon champion Elena Rybakina were high profile casualties.

After seeing Serena Williams stave off impending retirement by reaching the second round on Monday, big sister Venus was eyeing an 80th career win at the tournament.
However, Venus, who first played the US Open in 1997, was defeated 6-1, 7-6 (7/5) by Belgium's Alison van Uytvanck.