Russell Martin hit a three-run home run and A.J. Burnett pitched seven solid innings as the Pittsburgh Pirates grabbed the lead in the NL Central with a 7-1 win.
Pittsburgh now leads the division by one game over St. Louis, with a chance to extend the lead in Sunday's finale of this three-game set.
"We're heading in the right direction but we've got a long way to go," said Pittsburgh manager Clint Hurdle. "One of the things I share with new players coming in here is to fear nothing and respect everything and that's the way we'll keep doing it."
Burnett (7-9) gave up a run on four hits and a walk with six strikeouts and added an RBI single, while Neil Walker went 3-for-4 with an RBI for the Pirates, who have won three of their last four.
Lance Lynn (13-9) was tagged for all seven runs on 10 hits and three walks in just four innings of work for the Cardinals, who have dropped their past three. Carlos Beltran drove in the only run of the game for the team.
"They hit a couple of the ball really hard against Lynn today," said St. Louis manager Mike Matheny. "This was not what he was looking for when he went out there today."
The Pirates got on the board in the second inning thanks to consecutive RBI singles from Burnett and Jose Tabata for a 2-0 lead, but the Cardinals got one back in the third off of Beltran's run-scoring base hit.
Pittsburgh, though, responded with a big bottom of the third to take over the game.
Pedro Alvarez led off with a double and quickly scored on a single from Marlon Byrd. After Garrett Jones walked, Martin slammed a pitch over the wall in right-center for his 13th homer of the season.
After the next two batters recorded outs, Tabata singled and scored on a Walker triple for a 7-1 advantage.
St. Louis had just three baserunners after the third inning as Pittsburgh cruised to the victory.
The Pirates have taken 10 of the 15 games against the Cardinals this season ... St. Louis batted 4-for-12 with runners in scoring position ... Joe Kelly pitches for St. Louis in the finale on Sunday, while Kris Johnson counters for Pittsburgh.