Brandon Moss and Cliff Pennington each hit solo homers and Jarrod Parker tossed seven solid innings, as the first meeting of a crucial four-game series went the Athletics' way in a 3-1 victory over the Angels.
The AL wild-card leading A's have won four in a row since being swept by the Angels last week and climbed within three games of the front-running Rangers in the West Division.
Parker (10-8) held the streaking Angels to one run on three hits and two walks as Oakland won its 10th consecutive road game.
"Jarrod was aggressive. He wasn't afraid to pitch inside," A's manager Bob Melvin said. "This was a big win for us."
The Angels had won six straight to pull within one game of the Orioles for the final wild-card spot.
But Dan Haren (10-11) was unable to build off two straight winning starts, as he allowed three runs on four hits in 6 1/3 innings of work.
"They came out aggressive," Haren said. "You have to tip your hat."
Coco Crisp started Haren's night on the wrong foot when he took the first pitch of the game into right field and legged out a triple, then scored on Seth Smith's groundout to first.
Mike Trout walked with two away in the home third, stole second and moved to third when George Kottaras' throw trickled into the outfield. Torii Hunter followed with an RBI triple, but was left 90 feet from home when Albert Pujols popped up to second base.
Moss' 17th home run of the season leading off the fifth broke the 1-1 tie, as he easily cleared the scoreboard in right.
Pennington led off the next inning with another blast to right, though his landed in the first row of seats.
The A's have hit an MLB-leading 81 homers since the All-Star break.
Oakland wasted a bases-loaded, one-out opportunity in the seventh, but Ryan Cook and Grant Balfour each pitched an inning of relief behind Parker to finish off the win.
Balfour retired the side in order in the ninth to record his 17th save.
The 80-60 A's had not been more than 19 games over .500 since they finished the 2006 season 24 games over (93-69) ... Parker's two walks ended a string of nine straight games of A's starting pitchers having walked one batter or fewer ... Parker became the 10th rookie in Oakland history to win 10 games.