Queens, New York - Novak Djokovic and Coco Gauff launch their US Open title defenses on Monday, with the Serbian tennis superstar aiming to follow up his emotional Paris Olympics triumph with his first Grand Slam title of 2024.

Djokovic, seeded second behind world number one Jannik Sinner, is vying to become the first man to repeat in New York since Roger Federer won five straight US Opens from 2004-2008.

"Hopefully that changes this year," Djokovic said. "That's the goal."

It's been an erratic year for Djokovic, who was hindered by a knee injury and for the first time since 2017 is looking at the prospect of a year without a Grand Slam title.

The 37-year-old, whose 24 Grand Slam titles are tied with Aussie legend Margaret Court for most all-time, says he still gets pumped up for the "pillars of our sport."

And that's especially true of the US Open, where he'll anchor the night session taking on Moldovan qualifier Radu Albot.

"The US Open is a slam that holds the biggest tennis court in the world," Djokovic said of the energy on Arthur Ashe Stadium. "Night sessions at US Open are very famous. I can't wait to be under the lights. the noise, the energy of the stadium is just different from anything else."

Gauff, who has endured a dip in form since winning her maiden major last year, closes the afternoon session on Ashe taking on 66th-ranked Varvara Gracheva of France.

Austrian Dominic Thiem, the 2020 US Open champion, lost to 13th-seeded American Ben Shelton, who is aiming to improve on his scintillating semi-final run last year.

The match marks the final Grand Slam appearance for Thiem, who planned to retire at the end of 2024 after several injury-plagued seasons.

Shelton is just one of the US men out to end a US Open title drought that now stretches over two decades – back to Andy Roddick's 2003 victory.

Compatriots Taylor Fritz and Frances Tiafoe were also in action on Monday, 12th-seeded Fritz taking on Camilo Ugo Carabelli and 20th-seed Tiafoe – coming off a runner-up finish to Sinner at the Cincinnati Masters – facing Aleksandar Kovacevic.

"I think it's inevitable that we will have a Grand Slam champion from our country," Shelton said before the tournament. "I don't know when it's going to be or who it's going to be."

Other notable matches on Monday saw Australian Open champion Aryna Sabalenka of Belarus, seeded second behind world number one Iga Swiatek, taking on Australian qualifier Priscilla Hon and Wimbledon champion Barbora Krejcikova of Czech Republic facing Spain's Marina Bassols Ribera.

In early action, Olympic silver medalist Donna Vekic of Croatia moved smoothly into the second round with a 6-4, 6-4 victory over Australian qualifier Kimberly Birrell.

There was more Grand Slam disappointment for ninth-seeded Maria Sakkari of Greece, who retired with an apparent shoulder injury after dropping the first set against China's Wang Yafan 6-2.

Sakkari hasn't reached the second week of a major since the 2022 Australian Open.