ANAHEIM, Calif. -- The Los Angeles Angels became the first team in the major leagues to clinch a playoff spot on Monday night, with Matt Shoemaker pitching five-hit ball into the eighth inning of an 8-1 victory over the Seattle Mariners.
David Freese and Brennan Boesch homered for the big league-leading Angels (94-56), who reduced their magic number to three in the AL West race with their 11th victory in 12 games. Los Angeles is assured of at least a wild card berth in its first postseason since 2009.
The Mariners (80-69) dropped two games behind Kansas City for the second AL wild card spot with their fifth loss in six games.
Shoemaker (16-4), who turns 28 next weekend, improved his own franchise record for rookie victories with his ninth win in 11 appearances since July 26. He pitched seven shutout innings and didn't allow a runner to reach third base before Logan Morrison doubled and scored on two groundouts in the eighth.
Manager Mike Scioscia and the Angels' training staff came out to check on Shoemaker before he left after 7 2-3 innings.
Iwakuma couldn't get out of the fourth inning of his first career loss to the Angels, yielding six hits and seven runs. Humberto Quintero drove in Seattle's only run.
Iwakuma's career-long dominance of the Angels (5-0, 1.64 ERA) abruptly ended after he retired Los Angeles' first eight batters. The Japanese right-hander, who walked just 16 batters in his first 176 innings this season, walked Efren Navarro and Mike Trout with two outs in the third before Pujols cleared the bases with a shot down the left-field line.
Pujols held his hamstring while jogging slowly into second as Trout slid under the cutoff throw at home, but the three-time NL MVP left the game walking easily.
The speedy Campana replaced Pujols and scored on Kendrick's double. After Freese crushed his ninth homer to center in the fourth, the Angels loaded the bases for Campana, who delivered his first RBIs for his new team.
Boesch's first homer for the Angels put them up 8-0 in the fifth.
Mariners: Dustin Ackley returned to left field after missing six of the last seven games with a left ankle injury. He left in the sixth inning.
Angels: Josh Hamilton's injured right shoulder felt strong after three rounds of batting practice. The cleanup hitter might return as soon as Wednesday.
After three consecutive wins with their bullpen filling injured Garrett Richards' rotation spot, the Angels will try it again, starting with reliever Cory Rasmus (3-1, 2.80). Roenis Elias (10-12, 3.81) pitches for Seattle.