ST. LOUIS -- Milwaukee Brewers manager Craig Counsell said his hitters all had great at-bats in a seven-run ninth inning Sunday.

None of them were better than Jason Rogers' two-pitch appearance.

Pinch-hitting with the bases loaded, Rogers walloped a 425-foot grand slam to wipe out a St. Louis Cardinals lead and help Milwaukee take an 8-4 win at sold-out Busch Stadium.

It was the first career slam for Rogers, a rookie infielder who's 13-of-48 as a pinch-hitter with a pair of homers and eight RBIs.

"First career grand slam off a tough righty, one of the best in the game in (Trevor) Rosenthal," Rogers said. "It was special."

Rosenthal (2-4), St. Louis' closer, entered the game with a chance to set a single-season club record for most saves in a season with 48. But he never retired a batter, falling victim to wildness that set the stage for Rogers.

After Shane Peterson pinch-hit a leadoff single, Rosenthal beaned catcher Martin Maldonado with a changeup and walked pinch-hitter Jonathan Lucroy to fill the bases. Correctly figuring Rosenthal would be throwing strikes, Rogers hacked at the first pitch, fouling it off.

Rogers' swing at an 0-1 pitch connected solidly and there was no doubt the ball was gone, as it landed in the left-center field bleachers for his fourth homer.

"I missed the first pitch, but I made the adjustment and I was ready for the second pitch," Rogers said.

Left fielder Khris Davis, whose solo homer in the second initiated the day's scoring, capped the game-changing rally with a three-run blast to the seats in left-center, his 26th of the year.

"We were all having fun out there," Davis said. "It was a great feeling."

The feeling was somewhat less jovial in the Cardinals' clubhouse. Instead of leaving for their National League Central showdown series in Pittsburgh on Monday night with no worse than a three-game lead, their margin is down to 2 1/2 games, pending the outcome of the Pirates' game Sunday night at the Chicago Cubs.

"One game at a time," left fielder Stephen Piscotty said of St. Louis' approach. "We have to stay off that emotional roller-coaster. I think it's great we're playing these competitive games. It gets us ready for a series like this."

Piscotty followed up third baseman Matt Carpenter's tie-breaking solo homer with one of his own in the bottom of the seventh, giving the Cardinals (98-58) a 3-1 lead.

Starter John Lackey was in line for his fourth win of the year over the Brewers (66-90) after working seven solid innings for his 26th quality start in 32 outings. Lackey gave up five hits and a run with two walks and seven strikeouts.

Milwaukee starter Tyler Cravy left after three innings, yielding a hit and three walks while fanning two. The Brewers employed six relievers to cover the final six innings, with rookie David Goforth (1-0) earning his first big league win by throwing a scoreless eighth.

When St. Louis managed an unearned run in the ninth and pushed the tying run into the on-deck circle, closer Francisco Rodriguez entered and needed just two pitches to record the last out and bag his 37th save in 39 chances.

NOTES: St. Louis clinched a postseason home game with Saturday night's win over Milwaukee, even if it can't hang on to win the Central Division over Pittsburgh. It would host the Chicago Cubs in a wild-card game on Oct. 7. ... Milwaukee has had 11 players make their major league debut this year, a franchise record. That will become 12 Tuesday night in San Diego when RHP Jorge Lopez starts. ... The Cardinals didn't start LF Matt Holliday Sunday, although it was seen as a rest day after two straight starts. He'll likely be in the lineup Monday night when they start a showdown series at the Pirates.