Brandon Moss and Yoenis Cespedes homered and Dan Straily pitched into the seventh inning of his fourth major league start for the A's. Oakland emerged with its 11th straight road victory, matching the second-longest streak in franchise history.
Torii Hunter and Albert Pujols had run-scoring singles in the ninth for the Angels, who had runners at the corners and nobody out before Blevins relieved A's closer Grant Balfour and earned his first save since 2010 in dramatic fashion.
Coco Crisp hit a ninth-inning RBI triple and scored on Hunter's error in right field for the A's, who have taken two straight at Angel Stadium with a rookie starter on the mound.
This one wasn't nearly as tidy as Monday's 3-1 win, however.
Balfour walked Chris Iannetta and Mike Trout to open the ninth, and Hunter cut Oakland's lead to two runs with a single to center. Pujols then drove an RBI single to left, chasing the A's closer.
Blevins, who had just one save in his first 204 career appearances, struck out Kendrys Morales. Kendrick then grounded to third, and Oakland smartly turned the double play to end it.
Vernon Wells hit an early two-run homer and Hunter chased Straily with a seventh-inning shot for the
Straily (2-0) yielded seven hits and struck out eight in his first start since coming up from Triple-A Sacramento last week to take the rotation spot of injured right-hander Brandon McCarthy.
Oakland (81-60) has won 14 of 17 and 20 of 25, moving 21 games over .500 for the first time since the end of the 2006 season. The Athletics' grasp on a wild-card spot gets stronger with each game in Anaheim, and they're just three games behind Texas for the AL West lead.
The A's hadn't won 11 straight road games since 1981. They'll attempt to match the franchise record of 12 straight road wins Wednesday night when A.J. Griffin pitches against Los Angeles' Ervin Santana.
Trout had three hits for Los Angeles (77-65), which dropped 2 1/2 games behind Baltimore and the Yankees (79-62) for the second wild-card spot with its first back-to-back losses since Aug. 25-26. Tampa Bay (77-64) also is between the Angels and that wild-card slot.
Jerome Williams (6-8) couldn't make it out of the fourth inning in his first start for Los Angeles since July 19. The veteran gave up four runs and five hits, including four straight during Oakland's three-run fourth.
Cespedes hadn't homered in his previous 21 games until he connected in the second inning, his line drive barely eluding Trout's glove at the wall in center.
Wells put the Angels in front with a two-run shot down the left-field line in the second inning, his fifth homer in 15 games.
Williams was the Angels' fifth starter early in the season before injuries sidelined him, but he got a spot start when ace Jered Weaver skipped a turn to rest the tendinitis in his right shoulder.
After Moss hit his 18th homer, Josh Donaldson singled and scored on Stephen Drew's sacrifice fly off reliever Nick Maronde.
Hunter, who is hitting well over .400 in the past two weeks, connected for his 14th homer in the seventh.
But Crisp gave some much-needed cushion to the A's with his triple down the right-field line, where Hunter misplayed it and allowed Crisp to score.
NOTES: Williams hadn't pitched since Sept. 2. ... Trout added another spectacular catch to his large collection, diving forward to snag Cespedes' liner off the turf to end the fifth inning. ... Angels reliever Jordan Walden struck out the side in the eighth.