Saunders led off the game with a solo blast and Ackley put the Mariners ahead 5-0 with the fourth-inning grand slam.
Saunders connected for a second time in the fifth and later added a run-scoring double to finish with three RBI for the Mariners, who improved to 6-1 in their last seven games.
Hisashi Iwakuma (3-1) allowed one run on five hits over seven innings to earn the win, issuing three walks while striking out five.
Blue Jays starter R.A. Dickey (2-5) was pounded for seven runs on six hits over six frames, dropping his third straight start as Toronto fell for the 12th time in 15 contests, including four in a row.
Munenori Kawasaki provided the Blue Jays' only RBI.