Making just his third start after beginning the season on the disabled list with a neck injury, Matsuzaka tossed seven innings and struck out nine batters to help the Red Sox win their third consecutive game.
"It's an easy enough thing to say, but I have to perform well to keep my spot," Matsuzaka told reporters having missed a majority of last season because of injuries.
The Red Sox have picked up their form after a poor start and are 7-2 on their current homestand while improving to 5-0 against Toronto this season.
Boston (18-16) got off to a quick start by scoring twice in the first inning and Jason Varitek belted a solo home run in the second as the feasted on Toronto starter Dana Eveland, who lasted just four innings and allowed all six runs.
The Red Sox took advantage of eight walks by the Blue Jays and added a run in the fourth and two more in the fifth.
"It was nice, said Boston infielder Dustin Pedroia who had two hits. "We kept adding on and Dice kept attacking the zone."
The Blue Jays (19-16) notched their lone run in the sixth, when Fred Lewis delivered an RBI double as part of a 2-for-4 effort.
(Reporting by Jahmal Corner in Los Angeles; Editing by John O'Brien)