US player Serena Williams reacts as she withdraws from her women's singles first round match against Belarus's Aliaksandra Sasnovich on the second day of the 2021 Wimbledon Championships at The All England Tennis Club in Wimbledon, southwest London, on June 29, 2021. (ADRIAN DENNIS / AFP)

LONDON - Tennis great Serena Williams limped out of Wimbledon in tears on Tuesday after her latest bid for a record-equalling 24th Grand Slam singles crown ended in injury.

The American sixth seed and seven-times Wimbledon winner was clearly in pain on a slippery Centre Court and sought treatment while 3-2 up in her first round match against unseeded Belarusian Aliaksandra Sasnovich.

My love and gratitude are with the fans and the team who make being on centre court so meaningful. Feeling the extraordinary warmth and support of the crowd today when I walked on - and off - the court meant the world to me.

Serena Williams, American professional tennis player

Williams returned after a lengthy break but the distress was evident.

She grimaced and wiped away tears before preparing to serve at 3-3 after Sasnovich had pulled back from 3-1 down.

The 39-year-old, who had started the match with strapping on her rght thigh, then let out a shriek and sank kneeling to the grass sobbing, before being helped off the court.

"I was heartbroken to have to withdraw today after injuring my right leg," Williams wrote on Instagram.

"My love and gratitude are with the fans and the team who make being on centre court so meaningful. Feeling the extraordinary warmth and support of the crowd today when I walked on - and off - the court meant the world to me."

Great champion

Sasnovich, who practised her serve while Williams was getting treatment, commiserated with an opponent who had never gone out in the first round at Wimbledon in her previous 19 visits.

"I'm so sad for Serena, she's a great champion," said the world number 100. "It happens sometimes."

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Serena Williams plays a return to Aliaksandra Sasnovich of Belarus for the women's singles first round match on day two of the Wimbledon Tennis Championships in London on June 29, 2021. (KIRSTY WIGGLESWORTH / AP)

Eight-times men's singles champion Roger Federer expressed shock at Williams' departure and voiced concern about the surface, with the roof closed on Centre Court on a rainy afternoon.

His first-round opponent Adrian Mannarino of France also retired with a knee injury after a slip in the match immediately before Williams'.

"I do feel it feels a tad more slippery maybe under the roof. I don't know if it's just a gut feeling. You do have to move very, very carefully out there. If you push too hard in the wrong moments, you do go down," Federer said.

"I feel for a lot of players, it's super key to get through those first two rounds because the grass is more slippery, it is more soft. As the tournament progresses, usually it gets harder and easier to move on."

Williams has been a Wimbledon finalist in her last four appearances but her bid to equal Margret Court's record 24 Grand Slam singles titles has stalled since her last in Australia in 2017.

With the absence this year of world number two Naomi Osaka and third-ranked Simona Halep, hopes were rising of another year to remember for the American.

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"It was hard for me to watch that," said compatriot Coco Gauff. "She's the reason why I started to play tennis. It's hard to watch any player get injured, but especially her."