With the score knotted at 3 in the Cubs seventh, Erasmo Ramirez walked Kris Bryant and was lifted for Adam Kolarek. Anthony Rizzo greeted the lefty with an opposite-field single, and both runners advanced on Ben Zobrist's sacrifice bunt. Happ then lined a single to center to drive in Bryant and Rizzo.
Rizzo added a two-run double with two outs in the eighth.
Pedro Strop picked up the win in relief of starter John Lackey, who gave up three runs over six innings.