June 29 (UPI) -- Twenty-three time Grand Slam champion Serena Williams was forced to retire from her first-round match at Wimbledon 2021 due to an injury Tuesday in London. Women's No. 1 Ash Barty and men's No. 8 Roger Federer advanced.
Williams sustained what appeared to be a knee injury when she slipped on the wet grass court at the All England Club in the first set of her match against Belarusian Aliaksandra Sasnovich.
She attempted to play through the injury, but could not reach returns and was moved to tears when she tried to serve. She later fell for a second time, waved to the crowd and walked off the court.
"I'm so sad for Serena," Sasnovich said in her on-court interview. "She is a great champion. It happens sometimes in tennis. All the best to her and the best recovery for her."
Before Tuesday's early exit, Williams career featured just one retirement at a Grand Slam. She also exited early at Wimbledon 1998. Williams is a seven-time Wimbledon singles champion.
Earlier Tuesday, Barty beat Spain's Carla Suarez Navarro 6-1, 6-7, 6-1 in 1 hour, 44 minutes. The Australian faces Russian Anna Blinkova or Hungarian Timea Babos in the second round.
"She is a hell of a competitor and a hell of a fighter," Barty told reporters, when asked about Suarez Navarro. "It was a privilege to share the court with her today."
No. 13 Karolina Pliskova on the Czech Republic, No. 16 Elise Mertens of Belgium, No. 17 Barbora Krejcikova of the Czech Republic and No. 18 Maria Sakkari of Greece were among the top women to advance through Tuesday's early wave of first-round matches.
No. 23 Cori "Coco" Gauff, No. 26 Jessica Pegula and Shelby Rogers each won their matches, but fellow Americans Ann Li and Alison Riske suffered first-round losses.
Gauff beat Great Britain's Francesca Jones 7-5, 6-4 in a match that took one hour and 37 minutes. The 17-year-old Delray Beach, Fla., native recorded nine aces and 22 winners in the victory.
She battles Russian Elena Vesnina or Italian Martina Trevisan in the second round.
"I was just super nervous," Gauff said in her on-court interview. "I'm just happy I was able to come through with a win.
American Venus Williams also advanced with a three-set win over Romanian Mihaela Buzarnescu.
Venus entered the tournament with three losses in her last four first-round appearances at Grand Slams. The seven-time Grand Slam champion faces Tunisia's Ons Jabeur in the second round.
"You can't win them all," Venus told reporters. "Life is about how you handle challenges. Each point is a challenge on the court. No one gives you anything."
No. 2 Daniil Medvedev, No. 6 Alexander Zverev of Germany and No. 12 Denis Shapovalov of Canada were among the top men to advance Tuesday at the All England Club.
Federer said he was "lucky" to advance out of the first round, due to a walkover from opponent Adrian Mannarino of France.
Federer and Mannarino were tied at two sets apiece when Mannarino retired in the fifth set due to what appeared to be a knee injury. Federer fired 16 aces and 54 winners in the two-hour, 44-minute match.
"I wish him all the best and I hope he recovers quickly so we see him back on the court," Federer said in his on-court interview. "He could have won the match at the end obviously. He was the better player. I definitely got a bit lucky."
The 20-time Grand Slam champion battles France's Richard Gasquet in the second round.
First-round matches air through 4:30 p.m. EDT Tuesday on ESPN2. The first wave of second round matches air from 6 a.m. to 4:30 p.m. EDT Wednesday on ESPN.