Top-seeded Dominic Thiem of Austria advanced to the quarterfinals of the Rio Open with a hard-fought victory over Spain's Jaume Munar.
The runner-up in the Australian Open, Thiem best Munar 6-7 (5), 6-4, 6-4 in a match that took 2 hours, 41 minutes and ended early Friday.
Thiem clinched the win by breaking the serve of a tireless Munar in the last game. In the next round, he will face Italy's Gianluca Mager.
“I didn't play my best tennis, but it was enough,” the Austrian said.
He looked recovered from a left knee injury he picked on Wednesday after accidentally hitting one of the doors of the tennis court build in Rio's hypodrome.
Earlier, Mager topped Portugal's João Domingues 6-3, 7-6 (5).
Second-seeded Dusan Lajovic of Serbia was eliminated by Lorenzo Sonego. The Italian won 7-6 (5), 7-6 (5) and will play fifth-seeded Borna Coric of Croatia in the quarterfinals.
Coric beat home favorite Thiago Seyboth Wild 6-3, 1-6, 7-6 (5).