Milos Raonic fired 34 aces to grind out a 6-7 (4), 7-6 (4), 7-6 (4) win over second-seeded Kei Nishikori on Saturday to book his place in the Brisbane International final against Roger Federer.
The third-seeded Raonic appeared to grow in confidence as the match progressed, earning three match points with an ace in the third tiebreaker and then clinching it in 2-1/2 hours with a stunning forehand service return.
Top-seeded Federer later beat Grigor Dmitrov 6-2, 6-2 to advance to Sunday's title match. Federer lost last year's Brisbane final to Lleyton Hewitt.
Maria Sharapova was scheduled to play Ana Ivanovic in the Saturday night women's final.
It was Raonic's second win in six head-to-heads with Nishikori, who beat him in five sets in the fourth round at the U.S. Open en route to the final and again in the final of the tournament in Tokyo last year.
"We've played many times now, it's always been a long one," said Raonic, who concentrated on improving his serve over the off-season.
Neither player dropped serve in the match, meaning Nishikori exited the tournament without dropping a service game.
Eventually, though, the quick points Raonic was able to pick up on his booming serve made the difference.
The Canadian backed up his serve with 64 winners, twice as many as Nishikori, and had 38 unforced errors as he pushed the limits.
Each set turned on one error at the same stage of the tiebreakers.
Nishikori forced an error with a powerful service return in the first for a 5-4 lead. He served a double-fault in the second to give Raonic the 5-4 advantage with two serves to close.
Raonic got set point with a wide, kicking second serve that took Nishikori out of court and followed it up with a forehand winner.
Nishikori rushed to a floating backhand and over-hit it, allowing Raonic to level at 1-1.
The tiebreaker was on serve until Nishikori missed a forehand with the court wide open, and Raonic took over from there.
Venus Williams won her first title of the year when she recovered from a set and a break down for a 2-6, 6-3, 6-3 win over top-seeded Carolina Wozniacki in the final of the ASB Classic at Auckland, New Zealand.
Her sister, Serena Williams, was aiming for a third Hopman Cup title when she partnered John Isner in the U.S. team against Poland in the final later Saturday in Perth, Australia.