Serena Williams' comeback hit a bump with a loss in her opening-round doubles match at the Berlin Open.

Giuliana Olmos and Erin Routliffe defeated Williams and her partner Karolina Muchova 6-4, 6-4 to end Williams' involvement in the WTA 500 grass-court tournament at the first stage.

It didn't dim the love Williams was shown from the appreciative fans on what was her second appearance after a win at Queen's Club last week in London. That had been Williams' first professional match since the 2022 U.S. Open. But her participation at Queen's Club was cut short when partner Victoria Mboko injured her knee in a singles match.

The 44-year-old Williams was welcomed by a huge roar and applause to center court at the Steffi Graf Stadion, which quickly filled up as fans snacking and drinking outside realized the main attraction was about to start.

Earlier Tuesday, Wimbledon organizers announced that Williams and her older sider Venus, who turns 46 on Wednesday, were being given a doubles wild card invitation for the tournament that starts in less than two weeks.

“Welcome back Serena!” one fan in Berlin shouted as Williams showed flashes of her tenacity with some ferocious returns.

“Serena, we love you in Berlin!” another fan shouted to cheers in the second set. But Olmos and Routliffe broke Muchova's serve for 3-2 in the second set, and Routliffe set up the match point with an ace.

“Honestly, I felt pretty good out there,” Williams said in her post-match news conference. “I felt actually more nimble and more sturdy and quicker than the first match in Queens'. Yeah, overall, I feel pretty good. Just physically and quickness, which I think you need a lot of quickness on grass.”

Wimbledon calling

Williams won 23 Grand Slam singles titles — including seven at Wimbledon — before stepping away from the game, saying at the time she was “evolving” away from tennis rather than “retiring.”

She has also won 14 Grand Slam doubles titles, including six at Wimbledon — all with her sister Venus.

Williams still hasn't decided if she'll play singles again at the tournament.

“Oh my gosh, there are some left?” she replied when she was told there was still a singles wild card spot for Wimbledon. But then she mused about her readiness for it.

“Do you think I'm ready for singles?” she asked a reporter and then turned to Muchova to ask what she thought.

“I think I would be interested in it," the Czech player responded.

“That's the question of the hour, right?” Williams said of playing singles at Wimbledon. “I don't know. I don't know. I wonder why there's – I don't know.”