Jake Fraley and Spencer Steer hit RBI singles before Luke Maile hit a two-run homer in the fourth to give Cincinnati a 4-1 lead.
George Springer hit a two-run homer for Toronto and Danny Jansen added a solo shot.
Spencer Torkelson went 2-for-4 with a two-run homer for the Tigers, who head into Sunday's rubber match having dropped two of their past three contests.
Diamondbacks 4, Pirates 3Pavin Smith's go-ahead, two-run homer in the seventh lifted visiting Arizona to a win over Pittsburgh.
The Seattle offense was led by Eugenio Suarez, who was 2-for-4 with a two-run homer and three RBIs.