Donaldson also hit a solo homer in the first and went 4 for 4 with a walk and five runs for Toronto, which matched a season high with its third straight win.
Donaldson has three homers in two games and five game-ending homers, including two this season.
Jose Bautista went 3 for 4 with five RBIs in his return to the lineup after missing two games with a sore right shoulder, an injury treated with a cortisone injection.
With Toronto trailing 9-7, Josh Thole singled off Robertson (3-1) leading off the ninth and advanced on Jose Reyes' double. Donaldson followed with a drive into the right-field bullpen and was mobbed at home plate.
Steve Delabar (1-0) pitched 1 1-3 innings hitless innings.
Robertson blew a save for the second time in 11 chances, and Chicago lost for the eighth time in nine games.
