BRISBANE, Australia -- Nick Kyrgios overcame a knee problem to outlast fellow Australian Matthew Ebden 6-7 (3), 7-6 (5), 6-2 on Wednesday and move into the quarterfinals at the Brisbane International.
Third-seeded Kyrgios called for a medical timeout after nine games and had further treatment two games later to have his left knee taped.
His movement appeared to be hampered, but he still had too much for Ebden and set up a quarterfinal against former Brisbane International runner-up Alexandr Dolgopolov, who beat Horacio Zeballos 6-1, 6-2 in the second round.
Also Wednesday, former champion Milos Raonic lost in straight sets to 18-year-old Alex De Minaur in a second-round upset.
Raonic, who won the Brisbane title in 2016 and reached the Wimbledon final that year, struggled to find rhythm with his usually booming serve in a 6-4, 6-4 loss to the Australian wildcard entry.
De Minaur pressured Raonic with his relentless service returns and only dropped serve once -- when serving for the match at 5-2 in the second -- en route to the biggest win of his career.
The win put De Minaur into a quarterfinal match against American qualifier Michael Mmoh, who upset No. 8-seeded Mischa Zverev 6-2, 5-7, 6-4.
"It's going to take a while for me to believe what's happened just now," De Minaur said.
Raonic was playing his first match since October after taking time out to deal with injuries that also ruled him out of the U.S. Open last year, when his ranking slipped to No. 24 -- 21 spots lower than his career-high finish in 2016.
"Heavily disappointed," he said. "I could have served better. I could have moved a little better. I could have found my way to the net a little bit better.
"I sort of played into his comfort zone. I didn't do enough to pull him out of it or, when I did, it would be only for a few points at a time. I wasn't consistent enough and that's sort of what cost me."
Raonic saved double break points in his first two service games in the second set, but was finally broken in the fifth game when De Minaur challenged a call on a second serve, got it overturned to win the point on a double-fault, and won the next two points on the back of some impressive returns.
De Minaur broke again in the seventh game and, after missing the chance to close out in the eighth, the former Wimbledon junior finalist held his composure to close out.
Asked how he unsettled one of the better servers in tennis, De Minaur said he threw out the playbook.
"I was just guessing really, I'm not going to lie," he said. "I tried to change my returning position a bit to try to throw him off a bit. He probably didn't have his best serving day, which helped me a lot. I took advantage of it -- really proud."
Elina Svitolina advanced to the women's quarterfinals with a 6-3, 6-1 second-round win over Croatia's Ana Konjuh.
The third-seeded Svitolina, who won five WTA titles last year and peaked at No. 3, will next play fifth-seeded Johanna Konta.
Kaia Kanepi beat Lesya Tsurenko 6-4, 6-3, and qualifier Aliaksandra Sasnovich rallied for a 1-6, 7-6 (2), 6-3 win over Anett Kontaveit to set up a quarterfinal match against Alize Cornet.
Information from the Associated Press was used in this report.