Second seed Simona Halep has overcome a thigh injury and 30-degree heat to reach her first US Open quarter-final, where she will take on two-time runner-up Victoria Azarenka.
Halep needed 2hr 38 min, as well as a 10-minute heat break, to down German 24th seed Sabine Lisicki 6-7 (6/8) 7-5 6-2 on Monday.
Halep, 23, is the first Romanian in the last eight in New York since Irina Spirlea went to the 1997 semi-finals.
But she did it the hard way, letting two set points slip away in the first set before then requiring a medical timeout to have her left thigh tightly strapped.
There were 17 service breaks, nine of them in the second set, while both players committed a total of 105 unforced errors, 72 off the German’s racquet.
“It’s unbelievable to reach my first quarter-final at the US Open. It was a crazy match,” said Halep after her fourth successive win over the 2013 Wimbledon runner-up.
“I’m pretty tired but I would have been very unhappy with myself had I lost.”
Despite the injury, Halep insisted it was Lisicki who was the keener of the two to take advantage of the heat rule, which allows women players to leave the court for 10 minutes after the second set if the temperature goes beyond 30.1 degrees.
“She took the break so I went out too and cooled down.”
Azarenka reached her fourth US Open quarter-final with a 6-3 6-4 win over Varvara Lepchenko of the United States.
The former world number one, whose season has been stalled by a left thigh strain, appeared on Arthur Ashe Stadium with both biceps tightly strapped.
“It’s a little embarrassing. I have blisters from my shirts rubbing against my arms so I needed the bandages,” said Azarenka, the runner-up to Serena Williams in 2012 and 2013.
“It looks weird but I did what I have to do.”
Lepchenko, who was bidding to become the first American woman not called Williams to make the last-eight since 2009, was broken in the third and ninth games of the opening set.
She rallied to edge ahead in the first game of the second but handed the break straight back to the 26-year-old Azarenka.
The Belarus star, a two-time Australian Open champion, carved another break for 5-3 before faltering when she served for the match.
But she secured victory in the next game on her first match point when left-handed Lepchenko went wide.
Azarenka holds a 2-0 career lead over Halep, although their last meeting was back in 2012.
Czech fifth seed and double Wimbledon champion Petra Kvitova, who has dropped just 12 games in three rounds, takes on British qualifier Johanna Konta, the world number 97.
Victory would make Kvitova the first Czech in the quarter-finals since Daja Bedanova in 2001.
Konta will be Kvitova’s third opponent in four matches ranked outside the top 90.
The 24-year-old Australian-born Konta hopes to become the first British woman in the last-eight since Jo Durie in 1983.
The winner of that tie will face either Australia’s 22nd seed Samantha Stosur, the 2011 champion, or Italy’s Flavia Pennetta, the 26th seed.
Serena Williams features on Tuesday when the quarter-finals get underway, facing sister Venus for the 27th time as she continues her bid to complete the calendar Grand Slam.