Serena Williams' hopes of a victorious return to Wimbledon after a year out ended with a loss to Harmony Tan.

The American great, 40, returned to the same Centre Court where she had limped out injured last year with a passionate display in a 7-5 1-6 7-6 (10-7) defeat.

Willed on by a fervent crowd, Williams answered questions over her fitness with a dynamic display that put her two points from a win before Tan edged it.

The burning question now is surely 'was this her last Wimbledon'?

"That's a question I can't answer," she told a news conference. "I don't know.

"Who knows? Who knows where I'll pop up."

It is almost a year to the day since Williams limped tearfully off Centre Court after slipping and hurting her right ankle in her first-round match against Aliaksandra Sasnovich.

The crowd that day might have wondered if they would ever see the American great back at the grass-court Grand Slam, with age and injury against her.

Even she herself admitted while at Eastbourne this month - where she made her comeback in the doubles alongside Ons Jabeur - that she had harboured her own doubts.

But Williams walked on to the same court, where she has won seven of her 23 Grand Slam singles titles, to a rousing reception.

Now ranked 1,204th in the world, she had needed to request a wildcard to enter the draw.

And she soon showed why she was never going to be turned down.

Shaking off a slightly rusty start in which she was broken by the Wimbledon debutant in the first game, Williams found her feet - and her voice - as she roared when a smash sealed a break back.

The pair traded further breaks, with Williams hitting balls on the run, moving much better than a year out of the sport might have suggested, and delivering some of the trademark powerful shots that have made her one of her sport's all-time greats.

But a break for Tan in the 11th game left the Frenchwoman serving for the set, which she sealed with a forehand winner.

Such was the excitement at times during some lengthy and high quality points that the umpire even had to remind the packed Centre Court: "I know it's very exciting but as a courtesy to both players please be quiet during the rallies."

And that was before the roof went on before the start of the second set to raise the decibel level further.

Williams held quickly to love and then broke in a near 20-minute second game, which featured 12 deuces, on her way to a 5-0 lead. Tan, 24, earned a morale-boosting hold before Williams served out to take it to a deciding set.

The American, whose only matches in the past year were last week's two doubles, broke early in the third but tenacious Tan soon pegged her back.

Williams had celebrated as if she had won the match when she broke for 5-4 in the decider but it proved premature when, having led 30-15 while serving for the match, she was broken again.

Williams forged a 4-0 lead in the final-set tie-break but it slipped away as Tan delivered some stunning winners and the American netted a forehand on match point.

"For my first Wimbledon it's wow - just wow," said world number 115 Tan.

"It's a dream because, you know, I saw Serena on the TV when I was young. She's a legend. When you play her, I was scared. I mean, I was scared when I was on the court, but really happy to be there."

There had always been sense that Williams had unfinished business at Wimbledon after the way her tournament ended after six games last year and one of the big motivating factors behind her return was not wanting that to be her final SW19 memory.

She has always remained motivated by the desire to equal Margaret Court's all-time record of 24 Grand Slam singles titles, and her best chance of doing that is likely to be on a fast grass surface.

She can take some encouragement from the fact she stayed at a high level during a draining encounter that finished after 22:30 BST and lasted three hours 11 minutes.

But whether that is enough to keep her in the sport when she has huge business interests and family life to enjoy remains to be seen.

Asked whether she would be OK with this match being her last Wimbledon memory, she was categorical: "Obviously not. You know me. Definitely not.

"But today I gave all I could do, you know, today. Maybe tomorrow I could have given more. Maybe a week ago I could have given more. But today was what I could do.

"At some point you have to be able to be OK with that."

But she said coming so close to victory made her want to hit the practice courts and she did not rule out an appearance at the US Open in August-September.

"I mean, when you're at home, especially in New York, and the US Open, that being the first place I've won a Grand Slam [in 1999], is something that's always super special.

"There's definitely lots of motivation to get better and to play at home."