MILWAUKEE -- For the second straight night, the Milwaukee Brewers kept most of the St. Louis Cardinals' lineup in check, save for one player.

But while outfielder Jason Heyward inflicted the damage Tuesday night, it was unheralded rookie Tommy Pham who swung the big bat Wednesday, belting a pair of home runs in a 5-4 Cardinals victory at Miller Park.

"We're real happy we're able to put a young player in and watch him make the adjustments," Cardinals manager Mike Matheny said. "He's been doing some work trying to figure out some holes and figure out the league. He has obvious power. He's just an exciting player. He made a couple of real nice plays in the outfield."

Pham, who had just two home runs in his first 42 major league games, doubled that total in his first two at-bats Wednesday against Brewers right-hander Wily Peralta.

"That was the first time I faced him," Peralta said. "So far, he's good. Two (at-bats), two homers."

Peralta also gave up a home run to third baseman Matt Carpenter, part of a disappointing four-inning performance that resulted in five St. Louis runs on six hits and two walks with a pair of strikeouts.

"Wily had a rough night," Brewers manager Craig Counsell said. "He didn't have the sink we normally see on his fastball tonight so we saw some balls driven in the air which, especially against right-handed hitters, is something you don't normally see. The sinker is his pitch and that has to be a good pitch for him."

The Cardinals got 6 1/3 innings out of left-hander Jaime Garcia, who gave up four runs on eight hits and a walk while striking out four.

"We got a good start from Jaime," Matheny said. "He just had one rough inning. He did a real nice job after that."

Most of the damage came in the fourth.

The Cardinals were leading, 5-0, but singles by left fielder Khris Davis and right fielder Domingo Santana and an error on Carpenter put runners at the corners with nobody out for second baseman Elian Herrera, who dropped a fly ball in shallow right, between a trio of charging St. Louis defenders, making it a 5-1 game.

The next batter, catcher Martin Maldonado, made it a one-run game with a three-run home run to right-center, his fourth of the year.

Garcia recovered from there, retiring seven of his final nine batters.

"(Maldonado) put a good swing on a mistake that I made," Garcia said. "But at the same time, I was able to stay in the game. That didn't really affect me mentally or physically. I was able to make pitches as if nothing happened."

Milwaukee's bullpen put up five scoreless innings, but the Brewers couldn't close the gap against right-handers Seth Maness, Jonathan Broxton or Trevor Rosenthal, who struck out the side in the ninth for his 45th save of the year.

"We didn't have a big scoring opportunity after that inning," Counsell said. "We've done some good things the last two nights but not enough to beat a good team."

Second baseman Kolten Wong's one-out walk in the second set the stage for Pham's first home run of the day, which gave the Cardinals a 2-0 lead.

Third baseman Matt Carpenter made it a 3-0 game when he led off the third with his 22nd home run of the season. After Wong's one-out single in the fourth, Pham struck again, drilling a 3-2 slider to center, putting St. Louis up 5-0.

Pham nearly added a third home run on the day, driving a ball deep to center in the eighth that Logan Schafer hauled in at the base of the wall.

"I actually (thought it would be a home run)," Pham said. "The wind was blowing in late in the game and it held it up."

The victory moved St. Louis four full games ahead of the second-place Pirates, who fell to the Cubs, 3-2, in Pittsburgh.

NOTES: Brewers OF Ryan Braun was scratched from the starting lineup with lower back tightness. ... Milwaukee was also without C Jonathan Lucroy, who hasn't played since Sept. 8 because of post-concussion symptoms, and 1B Adam Lind, who sat against Cardinals LHP Jamie Garcia. Lind was batting .229 against left-handed pitchers this season and .299 against right-handers. ... Cardinals 1B Matt Adams was back on the bench Wednesday, a day after making his first start since May 26. Adams missed 91 games with a right quad injury and has served primarily as a pinch hitter since being activated last week.