Four finals have followed since but without Margaret Court’s record number of Grand Slam singles titles matched, the 24.
There has been no final since the 2019 US Open and, with every passing Slam, the doubts grow both externally and within Williams herself despite her insistence otherwise.
Like Roger Federer, the opportunities are thinning out, the pair both days away from the their 40th birthdays. The glaring difference is that Federer has not had to go through childbirth during that quest, making Williams’ position still towards the very top of the women’s game all the more impressive.
This year, her cause is aided by the fact that Halep is absent – injury forcing her out on the morning of last week’s draw – so too Naomi Osaka for a second Grand Slam as she battles with mental health issues.
Chris Evert, an 18-time Grand Slam champion herself – three of those coming at Wimbledon, said of the 39-year-old’s chances: “As with Roger Federer, I would give Serena a better chance at Wimbledon because the grass is perfect for her game.
“On the grass, if Serena is fit and that serve is working then that’s half of the match right there. She has that experience and flexibility. But the other players are better now than they were two years ago and they are not intimidated. They all feel they have a chance against Serena.”
Williams has cut down on her tournament time immeasurably. Now, it is always about the Slams, to the degree that she has ruled out the Olympics with the focus on Wimbledon and then the US Open.
It is to the extent that she has not played since being knocked out of the fourth round of the French Open by Elena Rybakina.
Assessing her own chances ahead of meeting Aliaksandra Sasnovich in the third match on Centre Court on Tuesday, Williams said she still felt like the marked player in the draw.
“I’ve had a big X on my back since ’99, since I won the US Open,” she said. “When players play me that hard every single tournament, every single match, every single Grand Slam, it doesn’t matter where you are, you just get better.
“The women’s draw is so deep, regardless of whom you play, you really have to show up now. There’s no longer matches that are going to be a sure walk through. You just have to really have your head in, have your game on. I feel like it doesn’t matter who you play, you have to be ready.”
For the No6 seed, greater challenges lie in wait than Tuesday’s opponent, who in theory should not pose too much of a threat, although Williams has suffered her fair share of early Grand Slam exits to take anything for granted.
Perhaps the biggest threat is No1 seed and tournament favourite Ash Barty, who has had even less game time than her rival coming in because of an injury which saw her retire from the French Open during her second-round match.
Barty is at the relative infancy of her Grand Slam career with just one title to her name. In contrast, Williams has seven Wimbledon titles alone. She would dearly love an eighth and that record-equalling 24th.