Vargas (12-7) allowed two runs on five hits over seven innings to extend Seattle's season-high winning streak to six games.
Dustin Ackley led the Seattle offense with three RBI, including a leadoff home run in the bottom of the first inning. The Mariners added three more runs in the second to take control of the contest.
Aaron Laffey (2-2) took the loss for the Blue Jays, who have lost three in a row. Laffey lasted 4 2/3 innings and surrendered seven runs on nine hits and two walks.
Brett Lawrie drove in both Toronto runs with a third-inning double into the left-field corner.