Lance Parrish drove in three runs with two home runs and Tom Brookens added three RBI to give Detroit the victory over the visiting Mariners.
Dan Petry raised his record to 13-7 with two innings of relief help from Pat Underwood, who earned his second save.
Rookie Howard Johnson singled in the first and Parrish hit losing pitcher Gaylord Perry's first pitch into the upper deck in left for his 23rd home run of the season. Brookens hit his eighth leading off the seventh inning to make the score 4-2 and drive Perry from the game.
Jerry Turner singled in the fourth and scored Detroit's third run on singles by Enos Cabell and Brookens.
Detroit added three more runs in the eighth. Parrish led off with his 24th homer. One out later, Chet Lemon singled to short, moved to second on Todd Cruz's throwing error on the play, advanced to third on a wild pitch and scored on a sacrifice fly by Rick Leach. Brookens' RBI single scored Enos Cabell with the Tigers' seventh run.
Seattle scored once in the third when Joe Simpson walked with one out, stole second and scored on Manny Castillo's single. They added another in the seventh on walks to Dave Revering and Rick Sweet, a sacrifice by Todd Cruz and a single by Julio Cruz.