Mauer (2-3) allowed just two hits to Texas in his previous outing, but both of those turned out to be homers and he eventually took the loss.
This time he was helped out by three double plays while giving up all seven of the Angels' hits over 6 1/3 innings. Carter Capps and Tom Wilhelmsen teamed for 2 2/3 innings of perfect relief.
Kyle Seager drove in three runs, one of them with a third-inning single and the other two on a homer in the eighth.
Carlos Peguero had a solo shot in the third and Jason Bay delivered a two-run single in the seventh.
The Angels have lost two in a row and the Mariners snapped a two-game skid.
Garrett Richards (1-1) endured the loss, surrendering five runs on nine hits in seven innings.