Matt Adams tied the score with a two-run homer off in the seventh for St. Louis' major league-leading ninth pinch-hit homer of the season. It also ended a streak of 13 innings of one-run pitching by Chicago starter John Lackey against his former team.
Grichuk drove a 2-2 pitch off of Adam Warren (3-1) for the win.
Trevor Rosenthal (2-1) pitched a scoreless ninth.
The Cubs' Ben Zobrist had three singles and a walk, extending his streak to 29 starts with reaching safely. He is hitting .387 during that span.
