OAKLAND -- Jean Segura scored the go-ahead run from first base on Guillermo Heredia's one-out double into the right-center-field gap in the 10th inning, as the Mariners topped the A's, 3-2, in Tuesday night's series opener.
Mike Zunino hit a game-tying two-run homer in the seventh, while Nick Vincent earned the win with 1 1/3 perfect innings of relief.
The Mariners won despite losing another key player to injury. Right fielder Mitch Haniger, who leads Seattle with 11 home runs and 36 RBIs, exited the game an inning after getting hit on the left wrist by a pitch from A's starter Trevor Cahill in the fourth inning.