For a fleeting moment, the U.S. Open felt like a time capsule. Serena Williams, stepping onto Arthur Ashe Stadium for the first time since 2022, and Carlos Alcaraz, returning from a four-month injury absence, turned the mixed doubles draw into a blockbuster event. Fans cheered wildly as the duo won their opening match, relishing the sight of the 44-year-old Williams unleashing strokes that echoed her prime and the 23-year-old Alcaraz fighting through visible rust. But the celebration was short-lived. On Tuesday, Williams and Alcaraz fell to Belinda Bencic and Flavio Cobolli in the quarterfinals, losing 5-4 (4), 4-1 in a match that highlighted the gap between star power and sharpness.

Cobolli, before the match, had called his opponents “the queen of tennis and the king of now,” a fitting tribute to two players who have combined for eight U.S. Open singles titles. Williams and Alcaraz had rallied from a slow start in the first round to defeat Erin Routliffe and Lloyd Glasspool 5-3, 4-1, with the crowd clearly on their side. “I never expected to be back on this court,” Williams said after that win. “I never thought this would happen.” Her return, limited to mixed doubles, raises the question of whether she might seek an encore in women’s doubles alongside her sister Venus. Williams has not ruled it out, but she has made clear she does not plan to play singles.

Alcaraz, the defending men’s singles champion and world No. 3, was playing his first competitive match since April 14, having missed the French Open and Wimbledon because of a right wrist injury. He wore a sleeve on that arm and admitted to extreme nerves. “I think everybody could see: I double-faulted on the first point,” he said. “I was really, really nervous. I was out for four months … I almost forget how it feels.” The pair’s chemistry was evident in flashes, but against Bencic and Cobolli, they struggled to maintain momentum. After dropping a tight first-set tiebreaker, they were overwhelmed in the second set.

Bencic and Cobolli, meanwhile, were in awe of the aura their opponents carried. “I don’t know how I landed on this court to play Carlos and Serena,” Bencic said. “It was an honor to play.” Cobolli admitted to feeling tight just because of the opposition. The match unfolded under the new mixed doubles format, which features sets to four games, a tiebreaker at 4-all, and a 10-point tiebreaker instead of a third set. Only the final on Wednesday night will revert to traditional six-game sets. The champions will receive $1 million, part of the tournament’s effort to attract top players to the event.

Williams, who won the U.S. Open mixed doubles with Max Mirnyi in 1998, showed glimpses of her old brilliance. She carried Alcaraz early on, hitting crisp volleys and dictating points. But the duo could not sustain that level. For Alcaraz, the match was a step in his recovery, though he acknowledged the journey ahead. “I almost forget how it feels,” he repeated, capturing the challenge of returning from injury. The crowd’s chants of “Come on, Carlos!” and “Let’s go, Serena, let’s go!” echoed through the stadium, but it was not enough to overturn the deficit.

As the tournament moves forward, the memories of this brief pairing will linger. Williams’ appearance at 44, even without singles, reinforces her enduring connection to the sport. Alcaraz’s return, though uneven, signals his determination to reclaim his form. The mixed doubles experiment, with its condensed format and lucrative prize, has given fans a unique spectacle—one that, for a few days, united generations of tennis greatness.