Novak Djokovic's quest for a century of ATP titles has been crushed by tennis feel-good story Reilly Opelka, who has instead served up an intriguing Brisbane clash of his own.

The giant American upset Djokovic 7-6 (8-6) 6-3 on Friday night to leave the 24-time grand slam champion stranded on 99 titles ahead of the Australian Open.

Opelka, the tallest man on tour standing at 211cm, is a former world No.17 on the comeback trail after hip and wrist injuries kept him on ice for two years.

He powered Djokovic off the court in a Brisbane International quarter-final boilover but could meet his match in big-serving French ace Giovanni Mpetshi Perricard.

Perricard hasn't lost his serve in the tournament and hit 75 aces in three matches, his campaign beginning with a clutch defeat of Nick Kyrgios on the Australian's injury return.

"He's a hell of a player," Kyrgios said of the 21-year-old.

"I have played (Ivo) Karlovic, (John) Isner, (Milos) Raonic - all the big servers - and he's got the biggest serve by far.

"He's found what works for his game style and he's committed to that.

"He's going to do some damage, for sure."

Defending champion Grigor Dimitrov, who has won the Brisbane event twice, has glided into the final four and will face Czech Jiri Lehecka for the other berth in the championship match.

World No.1 and two-time defending Australian Open champion Aryna Sabalenka showed deft touch to go with her trademark power in Friday's quarter-final, setting up a date with 17-year-old Russian rising star Mirra Andreeva.

Qualifier Polina Kudermetova will play Anhelina Kalinina, who pipped Australian Kim Birrell in Friday's other quarter-final.