Los Angeles won its fifth in a row and remained two games behind Oakland for the No. 2 wild card berth in the American League. The Angels are still alive in the AL West pennant race, trailing Texas by five games with seven to play.
Hunter's RBI single in the seventh rallied the Angels into a 3-3 tie and that was still the score when Stephen Pryor (3-1) came on to work the ninth for the Mariners.
Izturis opened the inning with a single, moved to second on a wild pitch and advanced to third on a sacrifice by Peter Bourjos.
Mike Trout was intentionally walked to get to Hunter, who hit a 2-0 pitch up the middle for the game-winner.
That gave the victory to Ernesto Frieri (5-2), who needed only five pitches to get through the top of the ninth inning.
Justin Smoak hit a solo homer for the Mariners in the fourth to give them a 3-2 lead.