NEW YORK (AFP) — Serena Williams said she is looking forward to a life beyond tennis after her dreams of a fairytale 24th Grand Slam victory at the US Open ended in defeat on Friday.

Williams, who turns 41 later this month, plans to "evolve" away from tennis following a US Open campaign that ended in the third round on Friday with a 7-5, 6-7 (4/7) 6-1 loss to Australia's Ajla Tomljanovic.

The 23-time Grand Slam singles champion said afterwards that while she was satisfied with her performances in New York, she was already eyeing her post-tennis life.

"It takes a lot of work to get here. Clearly I'm still capable," Williams said. "It takes a lot more than that. "

"I'm ready to, like, be a mom, explore a different version of Serena."

"Technically in the world I'm still super young, so I want to have a little bit of a life while I'm still walking."

While Williams said she hopes to remain involved in tennis in some capacity, in the near-term she plans to spend more time with daughter Olympia, 5.

"It's been really hard on her, my career," she said. "So it will be nice just to do that and spend some time with her, do things that I never really have done or had an opportunity to do."

Williams admitted however she was uncertain about what role tennis would play in her life.

"I've had so many amazing moments, that I don't see a future without it," she said. "What's my involvement? I have no idea."

Williams has stopped just short of definitively announcing her retirement, and once again deflected a question about whether there was any "wiggle room" in her apparent desire to hang up her racquet.

"I'm not thinking about that. I always did love Australia, though," she quipped in a reference to next January's Australian Open, a tournament she has won seven times.

Earlier, Williams had poured everything into one last stand in front of a ferociously partisan crowd at the Arthur Ashe Stadium during her three-hour battle with Tomljanovic.

After leveling the match in a marathon 1hr 23min second set, the veteran's resistance was finally broken in the third set as Tomljanovic raced into a 5-1 lead.

Even then, Williams summoned every last drop of her fighting spirit in an attempt to stave off defeat, saving five match points in the seventh game before finally succumbing.

Afterwards, Williams saluted the crowd, welling up as Tina Turner's anthem "Simply the Best" belted out around the stands.

"It's been a fun ride," Williams said. "It's been the most incredible ride and journey I've ever been on, I mean, in my life."

"I'm just so grateful to every single person that's ever said, 'Go, Serena,' in their life. You got me here."

Williams reserved special praise for her parents Richard Williams and Oracene Price who put her and elder sister Venus on the path to tennis superstardom.

"It all started with my parents," Williams said. "They deserve everything."

Of big sister Venus, she added: "I wouldn't be Serena if there wasn't Venus, so thank you, Venus. She's the only reason that Serena Williams ever existed."

Tomljanovic, 29, meanwhile expressed disappointment that Williams' career had drawn to a close.

"I'm feeling really sorry just because I love Serena just as much as you guys do," she told the crowd. "What she's done for me, for the sport of tennis, is incredible."