Pedro Alvarez hit a solo home run in the 19th inning to put Pittsburgh up 4-3, and Andrew McCutchen put the Cards in a three-run hole with a two-run single later in the inning. It was the only time either team scored more than two runs in an inning on the day.
Strong pitching had kept the score low. St. Louis' Jaime Garcia allowed two unearned runs five hits in eight innings, striking out 10, and Pittsburgh starter Jeff Karstens had given up two runs in seven innings. But the teams' respective bullpens kept the game scoreless from the top of the seventh inning until the 17th inning.
Barret Browning's entrance in the 19th, though, spelled doom for the Cardinals.
For a 19-inning game, this was not an extraordinarily weird one: Jon Jay, who went 3-for-9, was the only player with more than two hits on the day. McCutchen had just two hits, but they produced three RBI, and he and Garret Jones both drove in runs with infield singles.
Perhaps most strangely, Adam Wainwright entered the game in the 18th inning for the Cardinals as a pinch hitter, and drew a walk.
The victory gives the Pirates the inside track on the second Wild Card spot in the NL. The San Francisco Giants trail Pittsburgh by one game, and the Cardinals are two games back after losing two of three to the Pirates this weekend.