Phelps' base hit provided the Blue Jays with a 4-3 lead and they added a run on a double-play grounder by Jayson Werth. Wells' two-run homer in the seventh inning off Boston starter Frank Castillo (5-14) highlighted a three-run inning that opened an 8-3 advantage.
Toronto starter Esteban Loaiza (8-8) allowed three runs and nine hits in seven innings. Cliff Politte allowed a run in the eighth inning and Kelvim Escobar finished up with a perfect ninth.
Brian Daubach had three hits and Cliff Floyd homered for Boston, which fell to 27-29 since the All-Star break.