In the first game in league history that went to extra innings since the new rule placing a runner at second base went into effect, Oakland came out on the winning end.
Semien began the bottom of the 10th at second, and after Ramon Laureano was hit by a pitch and Matt Chapman struck out, a wild pitch allowed both A's runners to advance a base, placing the winning run on third.
Olson came up with a huge play in the top half of the inning, too. He fielded a hard-hit grounder by Jared Walsh and then made the heads-up throw across the diamond to Matt Chapman, who proceeded to catch Shohei Ohtani -- who began the inning at second -- in a rundown.
[RELATED: Davis, Kemp raise fist during anthem]
Quite the clutch season opener for Olson, who now is the answer to a trivia question.
[BALK TALK: Listen to the latest episode]
Watch Matt Olson hit historic grand slam to give A's 7-3 win vs. Angels originally appeared on NBC Sports Bay Area