Pinch-hitter Jorge Polanco and Cole Young hit back-to-back homers in the top of the ninth, lifting the visiting Seattle Mariners to a three-game sweep of the Detroit Tigers with an 8-4 win on Sunday.Polanco broke a 4-4 tie with his long ball off Tommy Kahnle (1-2). Julio Rodriguez homered for the third straight game and added an RBI double in the ninth. Randy Arozarena and Mitch Garver also homered for Seattle, while Matt Brash (1-0) picked up the win in relief.Seattle starter Logan Gilbert only allowed two unearned runs on six hits in 5 1/3 innings while striking out nine.Dillon Dingler drove in two runs and Riley Greene homered for the Tigers, who lost their fourth straight. Detroit starter Jack Flaherty gave up two runs and four hits in five innings with seven strikeouts.Detroit scored twice in the bottom of the first on Dingler’s two-out, two-run double.Rodriguez put Seattle on the board by ripping a Flaherty fastball over the right field wall for his 14th homer. The Tigers had three singles in the bottom of the inning but didn’t score.Gleyber Torres was thrown out by Rodriguez trying to advance from first to third on a single.