Simona Halep saved three match points before she eventually secured her passage to the Australian Open fourth round after a marathon 28-game final set against Lauren Davis.
The world No 1, who had won the pair’s only previous meeting at Indian Wells in 2013, has endured her travails in the opening week in Melbourne, she suffered an ankle injury in her first-round victory, but remains in with a chance of a maiden Grand Slam title.
Halep, 26, served for the match on three separate occasions in the decider but was pushed all the way by her unseeded American opponent in a 4-6 6-4 15-13 victory, which lasted three hours and 44 minutes.
“Definitely it was a very tough match. So long. I never played the third set so long,” Halep, who will next Naomi Osaka after the Japanese player ended the hopes of Ashleigh Barty in straight sets, said.
“I was very happy I could stay and win it. I’m almost dead but I’m happy we could show great tennis.”
The match, which opened the Rod Laver Arena schedule on Friday, included 48 games which ties the most for a women’s encounter in Australian Open history as two of the most diminutive players on tour played out an epic.
Halep served for the match at 5-4, 6-5 and 8-7 but was pegged back each time by the American, who showed immense belief, despite her inferior ranking, in cooler conditions at Melbourne Park after Friday’s extreme heat.
Davis appeared set to pull off the shock of the opening week in the women’s draw when she brought up three match points on the Halep serve at 10-11 but the Romanian fought back from the brink.
The 24-year-old American, forced to take an emergency medical time-out treat a toenail injury later in the final set, saved 15 break points during the absorbing match but began to lose her ease of mobility at 13-13, before Halep served out at the fourth time of asking.
Karolina Pliskova, also chasing her maiden Grand Slam title, won the all-Czech encounter against Lucie Safarova 7-6 (8-6) 7-5 in one hour and 37 minutes to reach the last 16.
Caroline Garcia, the eighth seed, was forced the distance by Belarus’ Aliaksandra Sasnovich but proved too strong with a 6-3 5-7 6-2 success and will next meet American 17th seed Madison Keys.
Keys, the US Open finalist last year, eased to 6-3 6-4 win over Romania’s Ana Bogdan in ruthless fashion and is pleased with her progress through the draw ahead of a first meeting with her French counterpart.
“I am always happy if I’m not the drama, and I feel like the U.S. Open I was the drama every night match that I played,” Keys said.
“It’s a good position for me to be in and I’m enjoying it.”