Frances Tiafoe hit back from 3-0 down in the final set to shock top seeded Stefanos Tsitsipas 3-6, 6-3, 6-4 and reach the Vienna ATP quarter-finals on Thursday.
Tiafoe, 49 in the world, now boasts a 2-1 head-to-head record over third-ranked Tsitsipas after coming out on top at Wimbledon before the Greek star gained revenge at the Tokyo Olympics.
The 23-year-old Tiafoe will next play eighth seed Diego Schwartzman, who defeated Frenchman Gael Monfils 7-6 (7/5), 4-6, 6-2.
"For me it was an important match. The only bad part is I cannot see Paris Saint-Germain tomorrow with Lionel Messi in France. I'm kidding, I'm kidding!" Schwartzman said in his post-match interview, referring to reaching the French capital ahead of next week's Paris Masters.
German second seed Alexander Zverev earned his 300th tour-level win by seeing off Alex de Minaur 6-2, 3-6, 6-2 to also reach the quarter-finals.
"This is definitely a massive milestone for me," Zverev said after firing 17 aces past the Australian.
© Agence France-Presse