SERENA WILLIAMS quest for a record-equalling 24th Grand Slam Singles titles later this month appears to be tough ask after the American ace retired injured in Sunday's Rogers Cup final (Aug 11).
The veteran conceded defeat to Canadian teenager Bianca Andreescu, trailing by a break at 3-1 in the opening set, after being forced to retire with a back problem.
Visibly plagued by back spasms during the Centre Court encounter, Williams lasted just 16 minutes.
And 19-year-old Andreescu rushed to comfort upset Williams instead of immediately celebrating in front of her home crowd in Toronto.
Williams addressed the spectators at the end and admitted: "I’m not a crier, but I’m sorry I couldn’t do it today. I tried, but I just couldn’t do it.”
Williams, who has leaped up the rankings to become the world no.10, had seen off Japan's Naomi Osaka 6-3 6-4 in her previous match, an eagerly anticipated semi-final showdown.
It was their first meeting since Osaka stunned the 37-year-old at last year's controversial US Open final, when Williams called the umpire a "thief" for docking a game off her.
Williams, recently dismantled by Romanian Simona Halep in last month’s Wimbledon final, is now going to have to rest to get fit for the next major - the US Open.
And although she has won the US Open six times, Williams has not been crowned the champion at New York's Flushing Meadows since 2014.
The 2017 Australian Open was her last major title, and since then she has fallen in two finals at Wimbledon as well as being beaten by hard-hitting Osaka at the US Open.
Williams' start to this season was heavily hindered by a knee injury, until she got her rhythm back at the All England Club to become formidable on grass until the one-sided final.
These back spasms now are another hurdle for Williams in her latest shot at trying to match Margaret Court’s record of 24 Grand Slam singles titles.
And with the US Open starting on August 26, the legendary Williams is in a race to be fit for a potential fortnight's run on New York's hard courts.