The Mariners completed a four-game sweep of the Tigers with a 9-6 win in Seattle.
Robinson Cano launched a two-run shot in the third and a grand slam in the seventh for the 38-and-37 M's, who moved above .500 for the first time this season.
Andrew Moore tossed seven innings of three-run ball to get the win in his MLB Debut. Ian Kinsler and Miguel Cabrera went deep for Detroit, which has dropped six straight. Daniel Norris took the loss.
The Tigers open a series tonight in San Diego.
Detroit (Fulmer 6-5) at San Diego (Perdomo 1-4), 10:10 p.m.