Trout's four hits gave him a batting average of .325, four points shy of the American League-leading mark of .329 held by Detroit's Miguel Cabrera.
With two games remaining, Trout has a chance to prevent Cabrera's bid for baseball's first triple crown since 1967.
Howie Kendrick added four hits with a pair of RBI for the Angels, whose chase for an AL wild card berth ended with the Oakland Athletics' Monday victory over Texas.
C.J. Wilson (13-10) earned the decision despite allowing five walks, yielding three runs (two earned) on six hits while striking out seven.
Mariners starter Felix Hernandez (13-9) was rocked for seven runs on 12 hits over 5 1/3 frames.
Casper Wells belted a homer for Seattle, which dropped the opener of a season-ending three-game series.