Athletics 3, Mariners 2 (12): Coco Crisp led off the bottom of the 12th inning with a home run to give Oakland a victory over Seattle.

Crisp lined the second pitch he saw from Hector Noesi (0-1) over the right-field fence and an umpire’s review confirmed that the ball was over the wall before caroming back into the field of play. Drew Pomeranz tossed a perfect top of the 12th inning as the Athletics evened their record at 2-2 and handed the Mariners their first defeat.

The Athletics tied the contest in the eighth inning when Yoenis Cespedes lined a triple into the right-center field gap. The game remained knotted until Crisp ended the suspense with the first walk-off homer of his career.

Seattle starter Roenis Elias gave up one run and two hits over five innings in his major-league debut and didn’t allow a hit over his first 4 2/3 innings until Nick Punto lined a single into left field. Sam Fuld followed with a low liner to center that got past Abraham Almonte and rolled to the wall and Punto easily scored while Fuld was called out at the plate while trying for an infield-the-park homer.

Almonte reached second leading off the game when Athletics first baseman Alberto Callaspo made a fielding error and Punto following with a throwing error. Almonte eventually scored on Robinson Cano’s infield out and drilled a run-scoring single in the fifth to make it 2-0 against Oakland starter Jesse Chavez, who allowed two runs (one earned) and five hits in six innings.

GAME NOTEBOOK: Mariners starting pitchers have allowed five earned in 25 innings over the first four games. … Athletics 3B Josh Donaldson was hitless in four at-bats and is 0-for-14 over the last three games. … Seven Seattle pitchers combined to walk 10 Oakland hitters.