Pittsburgh Pirates pitcher Thomas Harrington (78) celebrates with catcher Joey Bart, left, after getting the final out of a baseball game against the St. Louis Cardinals in Pittsburgh. Associated Press

PITTSBURGH — Joey Bart, Andrew McCutchen and Isiah Kiner-Falefa each drove in two runs, and the Pittsburgh Pirates handed St. Louis its fourth consecutive loss with an 8-4 victory Monday night.

Bart connected in the first inning for his first homer of the season. He also hit an RBI triple during Pittsburgh's four-run seventh.

Pirates right-hander Carmen Mlodzinski (1-1) pitched five innings of one-run ball in his first win as a starting pitcher. He was converted from a reliever to a starter during spring training.

Rookie Thomas Harrington pitched four innings for his first save in his second career game, helping the Pirates win back-to-back games for the first time this season.

Kiner-Falefa hit a two-run single in the second, and McCutchen added a two-run double in the seventh.

Cardinals left-hander Matthew Liberatore (0-1) struck out seven in 6 1/3 innings. He was charged with five runs and eight hits.

Masyn Winn and Yohel Pozo homered for St. Louis, and Brendan Donovan had three hits.

Pozo was brought up from Triple-A Memphis before the game. He hit a solo drive in the sixth for his first homer since his major league debut with Texas on Aug. 13, 2021.

Cardinals third baseman Nolan Arenado was scratched with what manager Oliver Marmol said was “illness and general soreness.”

Harrington got Willson Contreras to ground into an inning-ending double play in the seventh, and the Pirates broke the game open in the bottom half. Contreras went 0 for 4, and his batting average fell to .103.

Harrington became the first Pirates pitcher to record a four-inning save since Jason Christiansen on July 17, 1998, at Montreal.

Cardinals right-hander Sonny Gray (1-0, 5.73 ERA) faces Pirates ace Paul Skenes (1-0, 1.46 ERA) on Tuesday night.