Top seed Simona Halep back from brink in epic third-round clash against Lauren Davis

Top seed Simona Halep saved three match points to come back from the brink in an epic third-round Australian Open encounter 4-6, 6-4, 15-13 Saturday against Lauren Davis.

Courageous unseeded American Davis lost a middle toenail on her left foot and had to be treated twice by the physio as she threw everything at Halep in a third set that alone lasted 2hr 22min.

Halep three times stumbled when serving for the match and came under constant pressure as the world number 75 would not lie down, hitting 52 winners to all parts of the court.

The Romanian world number one, suffering with ankle problems, finally managed to serve out at the fourth time of asking after three hours and 44 minutes of incredible action that brought a standing ovation from Rod Laver Arena.

"I never played a third set so long. I'm almost dead," said the Romanian. "My muscles are gone. I don't feel my ankle any more."

Halep nows plays either 18th seed Ashleigh Barty of Australia or Japan's Naomi Osaka in the last 16 after the longest match of the women's tournament so far.

It eclipsed the 3hr 1min that fellow Romanian Irina-Camelia Begu took to defeat Ekaterina Makarova of Russia 3-6, 6-4, 8-6 in the first round on Monday.