Erlin (1-0), called up from Class AAA Tacoma, pitched well in his initial start for the Padres, holding the Blue Jays to two runs on eight hits. The 22-year-old left-hander didn't issue a walk and struck out four.
Dale Thayer tossed 1 1/3 scoreless relief frames but Luke Gregerson, filling in at closer for the injured Huston Street, struggled in the ninth.
Colby Rasmus, Maicer Izturis and Melky Cabrera each delivered one-out singles to pull within a run, but Gregerson recovered for his first save when Emilio Bonifacio lined out and Jose Bautista grounded out to end the game.
Everth Cabrera went 3-for-4 with a pair of run-scoring singles and Kyle Blanks added an RBI as the Padres clinched their three-game set.
Toronto's Mark Buehrle (2-4) absorbed loss, surrendering four runs (three earned) on 10 hits over six frames.
Rasmus and Adam Lind each had two hits and an RBI for the Jays.