Kevin Gausman (1-0) pitched six innings for his first victory in nine career appearances at Rogers Centre.
Britton took over in the ninth and Troy Tulowitzki hit a one-out single, Russell Martin followed with a walk and both runners advanced on a wild pitch. Britton held on for his fourth save, retiring Kevin Pillar on a grounder then getting pinch hitter and former teammate Steve Pearce on a fly ball.
Blue Jays left-hander Francisco Liriano (0-1), who allowed five runs in one-third of an inning in his season-opening loss to Tampa Bay last week, rebounded nicely against Baltimore. He struck out 10 and gave up two runs and five hits in 6 2-3 innings.