World number three Milos Raonic fought back from a set down to beat Rafael Nadal 4-6 6-3 6-4 and reach the semi-finals of the Brisbane International on Friday.
Defending champion and top seed Raonic will now aim to reach the final for a third consecutive year when he faces Grigor Dimitrov in the last four.
Nadal, appearing in his first event on the ATP Tour since October after a wrist injury curtailed his 2016 season, recently employed Raonic's former coach Carlos Moya and converted set point at the sixth attempt to move ahead.
The Canadian hit an impressive 23 aces in the match but had to fend off two break points before forcing a decider in which he won the opening game on Nadal's serve.
Raonic fought off a scare in game four before serving out the match to love for just a second career win against the Spaniard.
"I played very well and I did a lot of very good things," Raonic said. "I obviously served well and I started creating opportunities. I was dictating, which wasn't necessarily the case at the beginning."
Dimitrov earned his match-up with Raonic with a 6-3 4-6 6-3 win over Dominic Thiem.
Stan Wawranka had to fight from behind in order to advance, with Kyle Edmund winning a first-set tiebreak in their quarter-final.
US Open champion Wawrinka rallied back before closing out a 6-7 (2-7) 6-4 6-4 victory to set up a semi-final against Kei Nishikori.
Japanese third seed Nishikori faced a far more routine match, defeating wildcard Jordan Thompson 6-1 6-1 in just 61 minutes.