NEW YORK — Serena and Venus Williams were once again the main attraction at the U.S. Open, and defending men's champion Carlos Alcaraz wasn't going to miss it.

"I think there is no better plan (than) to watch the doubles, the Williamses once again, while getting a treatment," Alcaraz said after winning his match. "I'm going to be ready for that."

The doubles contest turned into a thriller. The sisters battled back to force a 10-point match tiebreaker, but blew a 5-0 lead in it and lost 6-3, 6-7 (6), 7-6 (10-7) to Hao-Ching Chan of Taiwan and Maya Joint of Australia on Friday night.

It was the sisters' first U.S. Open match since 2022 at the Grand Slam tournament they have won twice. They rallied from 4-1 down in the third set to tie it, but faltered late in front of disappointed fans desperately rooting them on.

"I think the crowd is pretty much what we expected. We expected a full stadium, everyone cheering for them, which, pretty much was that," Joint said. "But the atmosphere is something that, yeah, it's super special. Not really going to get again with many other players."

Serena, 44, returned to tennis this year, while Venus, 46, has continued to play on tour.

Perhaps it was their ages, Serena's long layoff, or nerves — but both sisters double-faulted during the tiebreaker after playing brilliantly late in the third set and in the first few points of the breaker. The U.S. Tennis Association said the sisters would not be available for comment.

Serena has now lost to Joint for the second time this summer. She fell to the Australian in three sets at Wimbledon in her return to singles play, and she and Venus then had to pull out of their doubles match there after Serena hurt her knee. That delayed their Grand Slam return until New York, where they won titles in 1999 and 2009 and are now 27-8 across their 10 appearances.

The match was given a spot in the night session at Arthur Ashe Stadium — practically unheard of for first-round doubles, a slot normally reserved for the biggest names in singles.

The sisters were once dominant in women's doubles, teaming for 14 Grand Slam titles along with Olympic gold medals in 2000, 2008 and 2012, and sharing the No. 1 doubles ranking for eight weeks. A first-round loss in 2022 appeared to have been their last appearance together, with Serena stepping away from tennis that year after winning 23 Grand Slam singles titles, the most by any player in the Open era. Since returning this summer, she has suffered two heartbreaking defeats alongside her older sister, having also lost in a match tiebreaker at the Cincinnati Open. Venus additionally lost in the first round of singles.

Champions lead the field into the fourth round

Alcaraz won easily, but two-time defending champion Aryna Sabalenka was finally challenged — by her opponent and by the smell of marijuana — in her victory.

Sabalenka beat Kamilla Rakhimova 6-3, 6-4. The No. 1 seed was pushed in a second set that lasted 54 minutes — a minute longer than her entire previous match. Trying to become the first player to win three straight U.S. Open titles since Serena Williams from 2012-14, Sabalenka will face Taylor Townsend in the round of 16.

Alcaraz reached the round of 16 by beating Wu Yibing 6-3, 6-4, 6-1. Back at this tournament after missing four months with a right wrist injury, the two-time champion will face No. 20 seed Tommy Paul, who edged No. 15 Alexander Bublik in five sets.

"To be honest I'm better than I thought," Alcaraz said.

Sabalenka smelled marijuana; Pegula struggled for tennis reasons

Sabalenka was serving in the third game of her match on Louis Armstrong Stadium when she tossed the ball but let it fall to the court. She did the same on the next point, clearly bothered by something, then approached the chair umpire to ask for help because she smelled marijuana.

"I was like, guys, you can do whatever, you can smoke whatever, you can relax as much as you can, but please, do not do it around the tennis courts," Sabalenka said when asked what she was thinking. "It's a bit tricky to handle that smell while you're trying to compete at your best."

Jessica Pegula, the No. 3 seed, fought back to beat 2021 runner-up Leylah Fernandez 1-6, 6-4, 6-3. Pegula, who lost to Sabalenka in the 2024 final and again last year in the semifinals, got off to a dismal start, landing only 5 of 16 first serves in the opening set.

Fernandez had not won a Grand Slam singles match this year until arriving in New York and was trying to reach the U.S. Open fourth round for the first time since falling to Emma Raducanu in the final five years ago. Pegula had handled her easily in their only meeting this year but said Fernandez showed her different looks that caused trouble.

"I didn't start off very well. It was tough," Pegula said. "I had to dig deep there in the second to turn that around, and it very well could have not turned around."

Pegula advanced to face Sorana Cirstea, the 36-year-old Romanian contemplating retirement after this season. Cirstea will have at least one more Grand Slam match after the No. 16 seed beat No. 19 Jasmine Paolini 6-3, 6-3.

Townsend reached the round of 16 for the second straight year by knocking off No. 15 seed Diana Shnaider 6-2, 6-7 (3), 6-3 and seemed eager for the matchup with Sabalenka.

"I'm so excited. I feel like I thrive in these moments," the American said. "I'm built for these moments and so now is my time, I'm ready to take it. I'm ready to go."

Wimbledon champion Linda Noskova and No. 11 seed Marta Kostyuk advanced, setting up a rematch of their semifinal at the All England Club. No. 7 seed Karolina Muchova, who lost that final, was ousted by No. 26 Emma Navarro.

Daniil Medvedev, the 2021 champion, beat Arthur Rinderknech 6-4, 6-4, 6-4. The No. 7 seed will face No. 11 Frances Tiafoe, who topped No. 22 Valentin Vacherot 6-4, 6-2, 6-4.

A resurgent Stefanos Tsitsipas, a former top-three player now working his way back up the rankings, reached the U.S. Open fourth round for the first time by knocking off No. 18 seed Jiri Lehecka. Tsitsipas will face No. 8 Ben Shelton, a 7-6 (3), 6-7 (5), 6-3, 6-4 winner over Denis Shapovalov in a match that ended at 2:07 a.m. — the record third match of the tournament to finish after 2 a.m., a stretch of late finishes that has renewed discussion around scheduling at the season's final Grand Slam.