Star pairings Djokovic-Sabalenka, Williams-Alcaraz suffer first-round losses in U.S. Open mixed doubles

Aryna Sabalenka and Novak Djokovic will have to hope to win another U.S. Open singles title. They were no match for two of the top doubles players in tennis.

Sabalenka and Djokovic started strong but couldn't hold on, falling 1-4, 4-2 (10-2) to Katerina Siniakova and Henry Patten on Tuesday in the first round of the mixed doubles tournament in New York.

Siniakova, ranked No. 1 in women's doubles, ended the match with an ace while serving to Djokovic.

"Kat acing Novak on match point was pretty fun," Patten said after the match, before a quick turnaround to play their quarterfinal match against the married pair of Elina Svitolina and Gael Monfils.

Serena Williams and Carlos Alcaraz got knocked out in the mixed doubles quarterfinals by Belinda Bencic and Flavio Cobolli 5-4 (4), 4-1 on Tuesday. Cobolli before the match called their opponents "the queen of tennis and the king of now."

Mixed doubles pairings are competing in a 16-team event, which offers a $1 million US prize to the winning team.

The tournament was overhauled last year in an effort to get more top singles players to compete. It was moved to a two-day event well before the singles main draw begins, with a scoring format that guarantees quick matches that shouldn't tax the players too much.

The matches in the first three rounds feature sets to four games, with a tiebreaker at 4-all and a 10-point tiebreaker instead of a third set. Only the final on Wednesday night will resemble a regular match, with traditional sets to six games.

Sabalenka, the two-time defending U.S. Open women's champion, and 24-time Grand Slam champion Djokovic are exactly the types of players the U.S. Tennis Association was seeking. They had the No. 1 seed based on the lowest combined singles ranking of any team, but their loss was far from an upset.

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Patten is ranked No. 1 in men's doubles, and he and Siniakova turned things around after Sabalenka and Djokovic stormed through the first set in 12 minutes, then got an early break in the second.

Doubles specialists such as Siniakova and Patten were shut out of the U.S. Open last year, when teams qualified directly based on the two players' singles rankings, or were given wild cards by the USTA. Sara Errani and Andrea Vavassori, who had won the title in 2024, were the only doubles players in the field after they were given a wild card to return, and went on to defend their title.

An eight-team qualifying tournament was added this year, giving two teams, comprised mostly of regular doubles players, the chance to earn their way into the main draw.

Svitolina and Monfils routed Filipina star Alex Eala and Canada's Félix Auger-Aliassime 4-1, 4-1 in their opening match.

Also, Karolina Muchova and Jakub Mensik edged Kristina Mladenovic and Marcelo Arevalo 4-1, 2-4 (10-7). The Czechs advanced to face the duo of Emma Navarro and Tommy Paul, who ousted fellow Americans Amanda Anisimova and Learner Tien 5-3, 4-2.