Paris, France, 5 June 2017 | Darren Walton, AAP

A hand injury has cruelled Sam Stosur’s French Open hopes and ended the veteran’s record 452-week reign as Australia’s queen of the court.

Stosur revealed she needed an ultrasound before suffering a painful fourth-round loss to Latvian young gun Jelena Ostapenko in Paris on Sunday.

The former Roland Garros runner-up was closing in on a fifth quarterfinal appearance in eight years before fading to a 2-6 6-2 6-4 defeat following a medical time-out after dropping the second set.

“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.

“So yesterday I barely hit and just tried to manage it, just tried to get through and did everything I could.

“But she started playing pretty well as well, so it made life extra hard.

“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.

“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.”

Stosur applied ice to her serving hand during the changeovers and said the injury impacted almost every shot, especially the 33-year-old’s most lethal weapon.

“Every forehand. And then it started to hurt my serve,” she said.

“And 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.”

A former Wimbledon junior champion, 19-year-old Ostapenko will face 11th-seeded former world No.1 Caroline Wozniacki on Tuesday in her maiden Grand Slam quarterfinal, while Stosur will ponder what might have been – and her next move.

The 2011 US Open champion and one-time world No.4 has held Australia’s No.1 ranking since usurping Casey Dellacqua in October, 2008.

But she will relinquish top spot to Daria Gavrilova when the new rankings are released next week.

It’s a tough changing of the guard for Stosur, with the Queenslander defeating 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.”

Gavrilova remains alive in the doubles in Paris and will team with Russian Anastasia Pavlyuchenkova to try to stop the run of Dellacqua and fellow Australian Fed Cup teammate Ashleigh Barty in a third-round clash on Monday.

Stosur is projected to drop to No.33 in the world – her lowest ranking since April, 2009 – after failing to defend her semifinal points from last year.

The veteran hopes her injury doesn’t rule her out of Wimbledon starting on July 3.

“I’m hopeful that it’s nothing too serious, obviously,” she said.

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