Juan Martin del Potro's summer renaissance continued on Monday as the unseeded Argentine advanced into the US Open quarter-finals when Austrian eighth seed Dominic Thiem quit their match with an injury.
Del Potro, the 2009 US Open winner, whose career has been interrupted by a string of wrist surgeries and needed a wild card to get into the year's last grand slam, has made the most of his opportunity by reaching the last eight without dropping a set.
The towering Argentine's path was made a little easier when Thiem retired with an apparent knee injury trailing 6-3, 3-2.
Del Potro will now await the winner between third seed Swiss Stan Wawrinka and Ukraine's Illya Marchenko.
Halep tops rival Suarez Navarro to reach quarters
Fifth-seeded Simona Halep beat 11th-seeded Spanish rival Carla Suarez Navarro 6-2, 7-5 on Monday to reach the quarter-finals of the US Open on Monday.
The 24-year-old Romanian was broken serving for the match at 5-4 but she broke right back, and after falling behind 0-30 in the 11th game swept the last four points in a row to end it.
Halep, who reached the semi-finals at Flushing Meadows last year, edged ahead in her rivalry with Suarez Navarro, now leading their head-to-head series 6-5.
"I'm really happy I could win this match. It's really tough to beat her. I just gave everything I had," Halep said in an on-court interview.
The in-form Halep, a three-time winner this year who owns a 23-3 record dating back to start of French Open, will play either top-seeded Serena Williams or unseeded Yaroslava Shvedova of Kazakhstan in the quarters.
The Romanian is bracing for a probable showdown with world number one Williams.
"The next round will be a very tough one, so I want to enjoy this victory today," said Halep.