Overbay finished the game 4-for-5 with seven RBI and three runs scored, while John McDonald added a three-run homer for the Blue Jays, who came into the game having dropped their previous two. Jose Bautista added his MLB-leading 38th home run of the year.
Brett Cecil (10-6) was the beneficiary of all the run support and tossed a solid game of his own, giving up two runs and nine hits with three walks and six strikeouts over 6 2/3 innings.
Dusty Brown clubbed a two-run double to account for Boston's offense, as the Red Sox fell for the second straight game.
Jon Lester (13-8) didn't last long in the start, as he was pounded for nine runs on eight hits with three walks in just two-plus innings. Coming into the contest, he was 5-1 over his past six starts against Toronto with a 1.98 earned run average.