For the last two years, Raonic had stalled at the third-round stage at Crandon Park. He withdrew last year due to strep throat and suffered an injury the year before.
Raonic, the No. 12 seed, needed just 56 minutes to complete the victory. He fired 10 aces and had service breaks on four of eight chances.
The Canadian produced 26 winners and lost just five points on his serve in the match.
"It was a good way to start the day with a quick win and an early match," Raonic said.
The Canadian blew through the opening set in 25 minutes and took only slightly longer to secure the second. Raonic broke for a 2-1 lead in the second set and didn't look back.
He said he was particularly pleased with his service game and felt he had made strides since his win over the 55th-ranked Spaniard in Davis Cup play last year.
"I've improved in general on second serve," Raonic said. "That allows me to better take advantage of my opportunities."
Raonic, who did not face a break point, will next play Germany's Benjamin Becker.
"It's going to be tough no matter who I play," he said. "I always know the opponents can play well. But it's up to me to do what I need to do to win.
"My good serving gives me confidence, it makes my days a lot easier."
The 23-year-old from Thornhill, Ont., played with a sleeve on his right arm for the second straight match.
"I was using a lotion and it didn't react well to the sun," he said. "The sleeve is just for protection, that's all."
In doubles play, the sixth-seeded duo of Toronto's Daniel Nestor and Serbia's Nenad Zimonjic were to play Robin Haase of the Netherlands and Britain's Jonathan Marray later in the day.