Denorfia singled to center off Javier Lopez with runners at the corner to break a 1-1 tie and give the Padres their second win in a row.
Nick Hundley had two hits and an RBI in the victory. Pitcher Robbie Erlin also drove in a run in his 5 1/3-inning start. Tim Stauffer (3-1) picked up the win in relief. Houston Street made his 27th save.