Yairo Munoz capped St. Louis' five-run ninth with a three-run drive, lifting the Cardinals to a 10-8 win over the Pittsburgh Pirates on Thursday night.
With runners on the corners and no one out, Munoz drove the first pitch he got from Felipe Vazquez (2-2) over the wall in center for the second homer of his rookie season.
Francisco Cervelli hit a tiebreaking three-run homer in the eighth to give Pittsburgh an 8-5 lead. But the Pirates couldn't hold on and lost in St. Louis for the fifth straight time and 12th in the last 14.
Josh Bell also homered for the Pirates.
Munoz also had a two-run single in the first inning. He had five RBIs in 21 games coming into the day.
Pinch hitter Luke Voit sparked the winning rally with a two-run single, trimming Pittsburgh's lead to 8-7.
Voit was called up from Triple-A Memphis earlier in the day. It was his first at-bat with the Cardinals this season.
Munoz followed with his game-ending homer, the first by a St. Louis rookie since Kolten Wong on July 8, 2014.
Mike Mayers (2-0), also recalled earlier in the day, picked up the win with 1 1/3 scoreless innings. He struck out two and needed just 12 pitches to record the four outs.
Pittsburgh rallied from an early 4-0 deficit thanks to Cervelli's homer.
Gregory Polanco had his first three-hit game for the Pirates since opening day. Vazquez suffered his fourth blown save in the last five chances.
Pirates RHP Jameson Taillon (2-4, 4.53 ERA) will face the Cardinals' Miles Mikolas (6-0, 2.58 ERA) in the second game of the four-game series tonight.