NEW YORK -- Serena Williams began her latest attempt to win a 24th Grand Slam singles trophy by beating Kristie Ahn in the first round of the US Open on Tuesday. Things didn't go as smoothly for her sister, as Venus Williams lost in the first round of the event for the first time in 22 attempts.
In her match, Serena Williams split the first 10 games before pulling away to win 7-5, 6-3. The victory was her 102nd at the tournament, breaking the tie she held with Chris Evert for the most by a woman in the Open era.
Williams hit 13 aces and lost only six points on her first serve.
"It's been years, since the '90s, since I won a match in straight sets," Williams said. "It felt really good. I was like, 'Serena, just be Serena and close it out,' and I know I can do that, so it felt really good."
Williams, who will turn 39 this month, has won the tournament six times and has been runner-up in each of the past two events. She is seeded No. 3 and hoping to tie Margaret Court's record of 24 Grand Slam singles titles.
"I was really happy with how I just fought for every point, no matter how I was playing," Williams said. "I was like, 'OK, Serena, just gotta get my Serena focus back,' so that's what I've been trying to work on today."
Venus Williams was beaten by No. 20-seeded Karolina Muchova 6-3, 7-5.
It was small consolation to Venus that by appearing in the tournament for the 22nd time, she broke the women's record in the Open era. She had been tied with Martina Navratilova. The 40-year-old Venus was the oldest player in the draw. She fell to 1-7 this year.
Serena Williams was among the few spectators for the match, having already won on Tuesday.
Later Tuesday, three-time US Open champion Kim Clijsters lost while playing her first Grand Slam match in eight years. The four-time major champion was beaten by Ekaterina Alexandrova 3-6, 7-5, 6-1.
Clijsters won the tournament in 2005, 2009 and 2010, and she retired after the 2012 Open. Now 37 and the mother of three, Clijsters embarked on a comeback this year, but she has lost all three of her matches.
"It's a process,'' Clijsters said. "That's what I told myself at the start when I took this challenge on: that it's going to take a lot of hard work and losses.''
Clijsters said she trained hard for the Open and was excited to play, even with no fans in the stands because of the coronavirus pandemic. She has been hampered this year by injuries, most recently an abdominal ailment that appeared to be an issue in the final set, when the pace of her serve dropped.
But Clijsters said she felt fine and that the only problem was Alexandrova, a tour veteran ranked 29th.
"She started serving a lot better, I felt,'' Clijsters said. "In the third set, I just felt like she was seeing the ball very well and hitting her targets all the time.''
The atmosphere was much different than at the Open in the years Clijsters won the title. She also won the 2011 Australian Open, and she is a former world No. 1.
There were no fans to offer encouragement when Clijsters let the second set slip away or as she faded at the end. One pivotal stat: She won only three of 15 break-point chances.
But Clijsters said she felt good about the quality of her tennis. She dominated from the baseline in the early going, was effective at the net and ranked the performance overall as her best this year.
"That's the most positive thing about it,'' she said. "You look at a loss in a little bit more of a mature way than maybe 10 years ago.''
Earlier Tuesday, Garbine Muguruza opened the second day of the tournament by dedicating her win to a former top-10 player who had just revealed her cancer diagnosis.
Muguruza, the No. 10 seed, defeated Nao Hibino 6-4, 6-4 and thought about Carla Suarez Navarro, who shared her diagnosis publicly earlier in the day. Suarez Navarro revealed in a tweeted video that she'll need six months of chemotherapy to treat Hodgkin lymphoma.
"I was expecting to see her in this tournament," Muguruza said. "You know, she's such a nice woman, so sweet, so kind, so humble.
"I, for sure, will dedicate this win to her because I want her to feel that we are behind her, that I am behind her, and I will go and see her at some point when it's fine."
Suarez Navarro, who will turn 32 on Thursday, was ranked as high as No. 6, and she has reached Grand Slam quarterfinals seven times, including at Flushing Meadows in 2013 and 2018.
Others advancing Tuesday included 2017 US Open champion Sloane Stephens, reigning Australian Open champion Sofia Kenin, No. 9 seed Johanna Konta and No. 16 Elise Mertens.
Stephens beat Mihaela Buzarnescu of Romania 6-3, 6-3.
Stephens won the title when she was ranked No. 83; she is seeded 26th this year. She played Tuesday on Court 17, and she said a match with few spectators required an adjustment.
"It's back to girls' 12, where it's you and your parents and the girl you're playing and their parents,'' Stephens said.
Information from The Associated Press was used in this report.