Tennis: World No 1 Simona Halep survives scare in epic marathon Australian Open match against Lauren Davis

Romania's Simona Halep celebrates after defeating United States' Lauren Davis in their third round match at the Australian Open. Photo / AP Photo

World No.1 Simona Halep has emerged from a titanic third-round scare from Lauren Davis to progress to the second week of the Australian Open - and a potential meeting with top Aussie Ashleigh Barty.

Halep, playing through an ankle concern, dropped the first set, fighting back to defeat the world No.76 4-6 6-4 15-13 across three hours and 44 minutes on Saturday in the match of the tournament so far.

The Romanian saved three match points at 11-10 in deciding set of the Rod Laver Arena classic, overcoming Davis after the unseeded American lost a toenail in the marathon third set.

"I'm almost dead," Halep said in an on-court interview on Saturday.

"I feel that my muscles are gone. My ankle, I don't know how it is because I don't feel it any more.

"I've never played a third set so long. I'm very happy I could stay and win it ... it was very nice we could show such good tennis."

The 135-minute second set lasted longer than all but six matches so far in the tournament.

Lauren Davis of the United States falls in her third round match against Simona Halep of Romania. Photo / Getty Images

The dramatic encounter tied Chanda Rubin's 1996 match with Arantxa Sanchez Vicario for most number of games in a women's singles match at Melbourne Park.

Davis was a fabulous contributor to the contest, unfortunately missing out on a first fourth-round appearance at a major.

The American smashed 52 winners and was warmly commiserated on her way off centre court.

Halep will play the winner of Barty's clash with Naomi Osaka, to be played later on Saturday on Rod Laver Arena.

“My muscles are gone. My ankle - I don’t know how it is because I can’t feel it... It's great to be in 4R."

The world number 1️⃣, @Simona_Halep wins an incredible match to keep her #AusOpen campaign alive. pic.twitter.com/ddtJTR3ewL

— #AusOpen (@AustralianOpen) January 20, 2018

Match of the tournament by a country mile thus far! Both superb athletes in Simona Halep & Lauren Davies. 3hrs 45mins of awesomeness!
Thank you ladies 🎾#AusOpen pic.twitter.com/xhjzWEG4YU

— Dom Lau (@domjlau) January 20, 2018

Gosh this match is good. Should go without saying, but easily the match of the year candidate so far. #AusOpen

— Ben Rothenberg (@BenRothenberg) January 20, 2018

My goodness. Halep serves for the match three times and is broken all three times. Davis earned that last break: huge effort, great speed and controlled risk. 8-8 in the 3d set. Turning into a classic.

— Christopher Clarey 🇺🇸 🇫🇷 🇪🇸 (@christophclarey) January 20, 2018