Scherzer (13-6) won his third straight start, limiting the Blue Jays to one run on five hits while walking two. The right-hander raised his strikeout total to 186 over 147 2/3 innings this season.
Jose Valverde picked up his 24th save in the ninth after the Tigers bullpen had yielded a pair of runs, securing Detroit's win in the opener of a three-game series.
Omar Infante drove in a pair of runs and Austin Jackson went 3-for-5 with a run scored for the second-place Tigers, who came into the game trailing the American-League Central-leading Chicago White Sox by two games.
Toronto's Rickie Romero (8-11) absorbed the loss, issuing eight walks over 5 1/3 frames. He surrendered five runs on seven hits.
Edwin Encarnacion socked his 32nd homer and David Cooper went 3-for-4 with an RBI for the Blue Jays.