St. Louis went down early after Carlos Martinez gave up his fourth home run of the season.
Martinez grooved an 0-2 fastball down the middle of the plate against Blue Jays catcher Russell Martin, which Martin deposited into the right-center bleachers to give Toronto a 1-0 lead. Martin's home run traveled an estimated 419 feet.
Martinez did not allow another run in the inning and has thrown just 28 pitches over that span.
The Cardinals did not score against Toronto starter Mat Latos in their first two innings at the plate despite getting two men on in the bottom of the second.