Toronto's Melky Cabrera went 4-for-5 with two RBIs against his former team as the Blue Jays outslugged San Francisco 10-6 on Tuesday.
Cabrera signed with the Blue Jays (16-24) in the off-season after his spell with the Giants ended with a 50-game suspension for using performance enhancing drugs last season.
Toronto starter R.A. Dickey pitched six innings and struck out 10 to get the win and snap San Francisco's (23-16) three-game win streak snapped.
In other Major League action, the New York Yankees rallied to beat Seattle 4-3 after Mariners ace Felix Hernandez exited with an injury.
Hernandez, who leads the American League with a 1.53 ERA, tweaked his back in the sixth inning and left with a 3-1 lead.
The Yankees surged into the lead in the seventh, tying the game with a two-run double from Robinson Cano and moving ahead on a Lyle Overbay sacrifice-fly.
CC Sabathia struck out 10 batters in 6 1/3 innings but took a no-decision for the AL East leading Yankees (25-14).
Two of baseball's leading pitchers stayed undefeated as Tampa Bay's Matt Moore improved to an AL-best 7-0 while Arizona's Patrick Corbin moved to 6-0.
Moore struck out eight in six innings and allowed three runs in the Rays' 5-3 win over Boston, while 23-year-old left-hander Corbin tossed seven scoreless innings in the Diamondbacks' 2-0 shutout of Atlanta.
At the plate, Carlos Gonzalez went 5-for-5 with two home runs to lead Colorado past the Chicago Cubs 9-4 while Andrew McCutchen blasted the game-winning home run in the 12th to lift Pittsburgh to a 4-3 triumph over Milwaukee.
(Writing by Jahmal Corner in Los Angeles; Editing by Peter Rutherford)