Raonic, seeded third, cruised past Slovakia's Lukas Lacko 6-3, 6-3 in just over an hour Friday.
The 22-year-old from Thornhill, Ont., once again used a dominant serve to beat his opponent, with 11 aces to only two for Lacko.
"I'm playing really wëll, and controlling with my serve," said Raonic. "I'm feeling physically good thought I've been playing a lot.
"Right now, I just want to keep doing a lot of things well and controlling the matches like I've done so far. It's been a good week but I'd like to take it farther."
Raonic will next face Croatian Ivan Dodig, a winner over Finland's Jarkko Nieminen 6-2, 7-6 (3). Dodig has won both of the pair's three matches, including a second-round victory over Raonic last June on grass at Eastbourne and a Barcelona win in 2011.
A win over Dodig would mark Raonic`s return to the Tokyo final where he lost a year ago to Kei Nishikori.
"It will be another tough match against Ivan," said Raonic. "I've never beaten him and would like to. But I have to play at my best and keep doing what's been working so far this week. I'll have to keep up my servin if I want to have any chance to go farther."
Raonic, ranked 11th in the world, is coming off a title at the Thailand Open on Sunday and improved his season record to 40-17. He's trying to earn one of the last spots in the World Tour Finals in London next month.
Against Lacko, Raonic never faced a break point from his 81st-ranked opponent. The loss to Raonic was Lacko's 14th straight against a top-20 opponent.
Raonic, who stands 5-0 in quarter-finals this year, has not lost a set this week. He took early control against Lacko with two breaks to earn the first set in 25 minutes.
He went up a quick break in the second for a 2-0 advantage, and later closed his match with a service winner.
Sixth-seeded Nicolas Almagro of Spain upset fourth-seeded Nishikori 7-6 (2), 5-7, 6-3 to ensure there will be no repeat of last year's final.
Top-seeded Juan Martin del Potro was playing Alexandr Dolgopolov of Ukraine later Friday.