Exhausted Halep beats Davis in record-equalling Open classic
World number one Simona Halep needed almost four hours on court to subdue the tenacious Lauren Davis in an Australian Open cliff hanger to set up a potential clash with Ashleigh Barty.
Halep and Davis slugged out a marathon encounter lasting three hours and 45 minutes on Rod Laver Arena, with the Romanian triumphing 4-6, 6-4, 15-13 to equal the Open's record for most games played in a women's match.
She served for the match at 5-4 in the third set but was broken by Davis, who later held three match points when leading 11-10 only for her opponent to fight back to level in the 22nd game.
Both players had emptied the tank by this stage, with Davis needing two medical time-outs for treatment on both of her feet, before Halep secured a break to lead 14-13 ahead of serving out the match in the next game.
"I'm almost dead," Halep said in an on-court interview .
"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 142-minute third set lasted longer than all but six matches so far in the tournament.
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.
Incredibly, Halep served for the set four times but did not hold a match point until the very last point.
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 match with Naomi Osaka, to be played later on Saturday on Rod Laver Arena.
Earlier, sixth seed Karolina Pliskova beat Czech Fed Cup teammate Lucie Safarova 7-6, 7-5 to move into the fourth round.
In a match dominated by serve, Pliskova fired down 11 aces and offered up only one break point opportunity as she reached the last 16 for the second successive year.
Keys goes through with straight-sets win
US Open finalist Madison Keys sent a message that her 2017 season-end form was no fluke, running roughshod over Romanian Ana Bogdan to make the last 16.
The 20-year-old Keys, the highest-seeded American remaining in the women's draw, did not drop a single service game against the 102-ranked Bogdan in the 6-3, 6-4 victory.
Returning to Melbourne Park after wrist surgery sidelined her from last year's Open, the 17th seed blasted her way into the fourth round with 29 winners and six aces on Margaret Court Arena.
Yet to drop a set through her first three matches, Keys' big-hitting from the back of the court wore down the inexperienced Bogdan, who was making her first appearance in the third round of a major.
"I definitely felt that way," said Keys, who made a run to the Open semi-finals as a teenager in 2015.
"But she was also getting to a lot of balls and definitely made me play my best tennis."