Samantha Stosur is in a race against time to be fit for Wimbledon after her French Open was sabotaged by a devastating injury that also ended one of the longest reigns in Australian tennis history.

Stosur's painful 2-6 6-2 6-4 fourth-round loss to Latvia's rising star and former Wimbledon junior champion Jelena Ostapenko robbed the 33-year-old perennial Paris threat of possibly one last crack at an elusive title at Roland Garros.

The 2010 runner-up also relinquished the Australian No.1 ranking she had held since October 2008 to Daria Gavrilova after failing to defend the feast of rankings points accrued from last year's run to the final four.

But it's a baffling career-first hand complaint that now threatens to also cruel Stosur's grasscourt season and the chance to add credibility to an otherwise lamentable Wimbledon legacy that is worrying Stosur most.

"I'm still hopeful," the former US Open champion said of her race with the clock to be ready for the grasscourt grand slam starting on July 3.

"I'm hopeful that it's nothing too serious, obviously.

"I'm still planning on sticking to my schedule. But until I know what it is, I can't really say anything."

Stosur seemed destined for a fifth quarter-final appearance in Paris in eight years after charging to a 4-0 lead inside 13 minutes on Sunday.

But after collapsing following a mid-match medical time-out - and dropping serve an uncustomary six times - the veteran revealed she had required an ultrasound before taking the court for her third and fourth round encounters.

"My hand's been sore for about three or four days, since the day I played doubles here," Stosur said.

"Don't know what's wrong with it. But from 5-1 in that first set, it was just really, really painful and just wasn't going away - every forehand and then it started to hurt my serve.

"Pretty much the only thing I could hit without too much pain was my topspin backhand.

"So towards the end, I started hitting backhands on purpose and that's obviously not the way that I normally play."

With the draw having opened right up - and no longer featuring a solitary grand slam champion - Stosur admitted her exit was especially tough to swallow.

"The extra frustrating thing is that I actually feel pretty good with everything else. I feel like I could go out and play again now. I feel great," she said.

"So to kind of be hampered by something that's just very strange and random and I don't know what it is, it's obviously really disappointing in an event where I feel like I had a really good chance to keep going and hopefully do really well."

After an unbroken 452-week as Australia's queen of the court, it's a tough changing of the guard for Stosur.

The Queenslander defeated Gavrilova in the Strasbourg final eight days ago before the Moscow-born 23-year-old bombed out in the first round at Roland Garros.

"Look, that (record) is something to be really proud of," Stosur said.

"It's a really long time obviously and I managed to stick through that.

"So 'Dasha' can take it right now and we'll see where things lie."

Stosur is projected to drop to No.33 in the world - her lowest ranking since April 2009 - while Gavrilova is provisionally expected to remain at No.22 and secure a Wimbledon seeding for the first time.

AAP