Pirates 5, Cardinals 0: Pedro Alvarez continued to torment St. Louis pitching, launching a three-run homer as host Pittsburgh moved within one game of the Cardinals in the National League wild-card race.

Wandy Rodriguez (9-13) pitched six shutout innings to earn his first win as a starting pitcher for the Pirates, who beat St. Louis for the second straight night.

Alvarez followed walks to Travis Snider and Garrett Jones in the third with a mammoth blast off Joe Kelly (4-6) into the top of the right-field bleachers to give the Pirates a 4-0 advantage. Alvarez hit two homers in Tuesday’s game and has seven homers and 23 RBIs in 15 games against St. Louis this season.

Alvarez doubled in the fifth and scored on a single by Josh Harrison to make it 5-0.

Rodriguez allowed three hits and three walks while improving to 2-4 with the Pirates since being acquired from the Houston Astros. His previous victory came in relief when Pittsburgh beat St. Louis in 19 innings on Aug. 19.

Three relievers combined to throw three innings of two-hit relief as the Pirates improved to 63-0 when leading after eight innings.

Jones hit a first-inning double for Pittsburgh’s initial run.

Kelly allowed five runs and eight hits in five innings.

GAME NOTEBOOK: Pittsburgh OF Andrew McCutchen had one hit in the finale and went 5-for-13 in the series. … Cardinals C Yadier Molina missed the game with neck and shoulder soreness one day after being involved in a collision with Harrison. He passed the club’s concussion tests. … Pirates 2B Neil Walker (back) missed his third consecutive contest. … St. Louis OF Matt Holliday went hitless for the second straight game after recording nine RBIs in his previous five contests.