The fourth seed from Thornhill, Ont., had 15 aces in the match. He lifted his game in the second set after an evenly contested opener.
"Obviously, I am happy with the result," Raonic said. "There were a lot of things to be happy about, but a lot of things that I need to address for tomorrow.
"Today, I think I served a lot better but I was struggling to choose the right shots. Sometimes I was hesitant and sometimes I was rushing too much, making it difficult for myself."
Raonic will play second-seeded Nicolas Almagro in the semifinals Saturday. The 10th-ranked Spaniard laboured to a 4-6, 7-6 (8), 6-4 win over Japanese qualifier Yuichi Sugita.
The 21-year-old Raonic rose from No. 156 to a career-high 25th in 2011 and was named the ATP Newcomer of the Year. He is currently ranked 31st in the world.
It was Almagro's first match at the tournament, after receiving a first-round bye and winning on a walkover in the second round. Sugita squandered his chance to win in the second-set tiebreaker, allowing Almagro to close it out on his fifth match point.
Japanese qualifier Go Soeda upset defending champion Stanislas Wawrinka of Switzerland 6-4, 6-4.
The 120th-ranked Soeda broke in the third game of the first set and the ninth game of the second after twice earlier trading breaks with the Beijing Olympics doubles gold medallist.
"He deserved to win, he was playing better and was putting a lot of pressure on," Wawrinka said. "It happens this is just the beginning of the year. You are looking for matches, looking for rhythm, looking to play a good game."
Soeda will now play top-seeded Janko Tipsarevic in the semifinals after the Serb beat Belgian wild-card entry David Goffin 6-2, 3-6, 6-2.
"I am really happy — my first Tour semifinal and beating the world No. 17," Soeda said.
With files from The Canadian Press.