CINCINNATI • In 12 pitches it was over. Or maybe it's just begun.

It took the Cardinals only 12 fourth-inning pitches to score six runs behind Chris Carpenter and virtually decide the outcome in a 7-3 victory Monday night over Cincinnati.

The division-leading Reds didn't need that long to perhaps rouse a team from its somnambulant season.

Before a primed crowd of 36,353 at Great American Ball Park, the Cardinals used one explosive inning to take charge of the game and a pivotal three-game series.

Six straight hits against rookie Mike Leake, capped by second baseman Skip Schumaker's first career grand slam, detonated the inning and placed Carpenter on cruise control for his ninth consecutive win in as many appearances against his team's match-race opponent.

"They're in front of us. They're in our way," said Cardinals first baseman Albert Pujols, who contributed two hits, a walk and his team's final RBI. "This is the way we've been playing since the (All-Star) break. Obviously, it's always good to play these guys, because they're the guys in front of us. You need to bring your ‘A' game to the field."

Just as good, the Cardinals brought Carpenter, halving the Reds' lead in the NL Central to one game. If they didn't make a statement, they certainly slowed the division leaders' breakneck momentum. The Reds entered having won nine of their last 11 games and were 11-1-1 in their last 13 series. The Cardinals continue to seek traction on the road, where they have won one series since June 24.

"To their credit, they've played very well and been very consistent," manager Tony La Russa said. "If we get another game in this series, that's a nice piece of work. That's our goal.

"It'll be difficult to get another one. Hopefully it will be just as difficult for them to get one from us."

Carpenter won his ninth consecutive start against the Reds, and has compiled a 1.25 ERA against them in that span.

Leake (7-4) needed six pitches to clear the first inning and 26 to get through the first three before unraveling in the interminable fourth. Leake, after striking out shortstop Brendan Ryan for the inning's second out after enduring most of the Cards' barrage, forgot the number of outs and began to jog to the dugout. The righthander then surrendered a single to third baseman Felipe Lopez and was lifted by manager Dusty Baker before suffering further embarrassment.

Every Cardinals starting position player except Ryan hit safely and scored. Five managed multiple hits, including catcher Yadier Molina, who is hitting .355 since the All-Star break.

The Cards perfectly executed an early attack plan against Leake, who was dominant before the All-Star break but has been increasingly vulnerable since. They noticed a flattening of Leake's assortment in his previous start and adopted a very aggressive tack. Leake failed to escape the fourth inning.

"That was the game plan from the very beginning," Schumaker said. "He's a strike-thrower. He gets a lot of ground balls. He's very effective and he knows how to pitch."

Schumaker, who crashed his fourth home run, took a cortisone injection into his injured left wrist before the team's series against Florida last weekend and again received treatment immediately following Monday's game. He admitted shock about his opposite-field drive reaching the Reds' bullpen for a 6-0 lead.

"Everyone gets lucky now and then in their career,'' he said. "I probably hit it in the right park and it worked out for me."

The Cardinals' fourth-inning rat-a-tat opened with right fielder Jon Jay's double and Pujols' single.

Left fielder Matt Holliday drove in the game's first run with a single before Pujols raced home from second base on center fielder Colby Rasmus' single on a shoe-top fastball.

The Cardinals iced the game on the unprecedented exacta of Molina's infield single to deep shortstop and Schumaker's opposite-field drive. The Cards tacked on one more run in the inning, on a single by Pujols. They managed eight of their 12 hits in the fourth inning.

By extension, the night worked extremely well for Carpenter (13-3), now 11-3 in 17 career starts against the Reds and 17-2 in 27 starts within the division the last two years.

"I felt like I had a good game plan. I felt I executed early," Carpenter said. "We threw up seven runs early and it just made it that much easier to stay aggressive and continue to get outs."

Despite his success against the Reds, Carpenter became noticeably perturbed as the Reds broke his shutout and ended his night with a two-run seventh inning. Carpenter screamed as the Reds scored their second run and was lifted for a pinch hitter after seven innings and 98 pitches.

"I didn't want to give up any runs," he said. "I felt I was throwing the ball well. My pitch count was low. I just wanted to keep going. Unfortunately I found a way to get my pitch count up and get myself out of the game."

The Cardinals, meanwhile, have won Carpenter's last six starts. Four times during the span he has received the decision. Carpenter has allowed nine earned runs in 451/3 innings (1.79 ERA) during the tear.