Britain's Jack Draper defeated 2020 US Open champion Dominic Thiem 6-1, 6-4 on Wednesday to reach the ATP Winston-Salem Open quarterfinals.
The 20-year-old Englishman, who reached his first ATP Masters Series quarter-final two weeks ago at Montreal, ousted the Austrian who won his first major title two years ago in New York.
Thiem missed most of last year with a right wrist injury, including the chance to defend his US Open title.
World number 231 Thiem hadn't played a hardcourt match since March 2021 until this week but advanced to the third round when top seed Grigor Dimitrov retired in the second set of their second-round match.
Dutch second seed Botic van de Zandschulp advanced by beating Spain's Jaume Munar 6-3, 6-3 to book a quarter-final match against French 10th seed Benjamin Bonzi, who dispatched Brazil's Thiago Monteiro 7-5, 6-2.
Two other Frenchmen advanced with Richard Gasquet rallying past American Steve Johnson 6-7 (3/7), 6-4, 6-3 and Adrian Mannarino ripping Spanish eighth seed Albert Ramos 6-3, 6-3.
Mannarino will next face US fourth seed Maxime Cressy, who ousted Italy's Lorenzo Sonego 6-7 (4/7), 6-2, 7-6 (7/3) while Gasquet faces Serbian Laslo Djere, who outlasted Australian Jason Kubler 7-6 (7/4), 6-7 (9/11), 6-3.