Top-seeded Dominic Thiem of Austria was eliminated by Gianluca Mager of Italy in their rain-affected, two-day Rio Open quarterfinal on Saturday.
Mager, a qualifier, led 7-6 (4), 2-1 when rain forced the match to be suspended on Friday. He won the second set 7-5 on Saturday to reach the semifinals.
“I am speechless,” Mager said. “Playing against him was already a dream. I watch him on TV all the time.”
Thiem declined to speak to media. Defeat also cost him the chance to overtake Roger Federer for the No. 3 world ranking.
The 128th-ranked Mager will face Spain's Pedro Martínez Portero or Hungary's Attila Balazs. Portero was to resume their quarterfinal up 6-2, 2-2 after it was also suspended on Friday.
The other semifinal features third-seeded Christian Garin of Chile and fifth-seeded Borna Coric of Croatia.