Los Angeles jumped to a 9-1 lead through three innings and coasted to its second straight win.
Morales hit his 17th home run of the season in the first inning and Iannetta hit his seventh in the third.
The Angels had 14 hits in bringing C.J. Wilson an easy victory. Wilson (10-9) gave up three runs on eight hits over six innings.
Boston's Zach Stewart (1-3) made his 20th appearance of the season, but only his second start. He was pummeled for nine runs on 10 hits in just three plus innings.