Hunter led off the inning with his 15th home run of the season and capped the six-run outburst with a single.
The victory enabled the Angels to avoid a four-game sweep at the hands of the A's.
Jered Weaver (17-4) collected the victory, combining with relievers Kevin Jepsen and Nick Maronde for a four-hitter. Weaver, who tied Tampa Bay's David Price for the American League lead in wins, allowed just two hits and one walk in seven innings. He struck out nine.
Brett Anderson (4-1) was charged with five runs and nine hits and kept the Angels off the board until the six-run seventh.
Vernon Wells added another base hit. Anderson struck out Chris Iannetta but then walked Mike Trout to load the bases. Jesse Chavez was brought in in relief and Alberto Callaspo delivered a two-run single and Trout scored on a passed ball. Albert Pujols walked to push Callaspo into scoring position for Hunter's RBI single.