Wilson (5-4) allowed just one hit, walked two and struck out seven before turning over the ball to Frieri, who fanned two of the three batters he faced.
Albert Pujols hit a solo home run and finished with two RBI for the Angels, who had 10 hits in the game and ended a three-game losing streak. Erick Aybar, Howie Kendrick and Mark Trumbo drove in a run apiece.
Cliff Pennington singled in the second for Oakland's only run. The A's saw their two-game winning streak broken.
Graham Godfrey (0-4), called up from Triple-A Sacramento prior to the game, was roughed up for four runs on six hits and three walks in three innings to take the loss.