St. Louis won the opener of the four-game series 13-1.
CINCINNATI -- Maybe it was only one good night for the St. Louis Cardinals, who didn't want to read too much into their most lopsided victory of the season.
The scoreboard suggested otherwise.
Yadier Molina homered during a tone-setting, five-run first inning Monday night and drove in four runs overall, leading St. Louis to a 13-1 victory over the Cincinnati Reds and the early advantage in their pivotal matchup.
Chris Duncan, Scott Rolen and Scott Spiezio also homered for the NL Central leaders, who extended their lead over second-place Cincinnati to 4 1/2 games. The rivals play seven times -- four in Cincinnati, three in St. Louis -- during the next two weeks.
"The first game is an important game in any series," said Rolen, who had three hits. "I don't know if it sets the tone or not."
It showed what can happen when the Cardinals are at their best.
Right-hander Jeff Weaver (2-2) gave his best performance since joining the Cardinals in a July 5 trade with the Angels. He allowed six hits, including Javier Valentin's solo homer, in six innings on a muggy night.
"It's an important game at this point of the season, not only for us but just psychologically for myself," said Weaver, who struggled with the Angels. "I'm still not exactly where I want to be. It's a step in the right direction."
The offense was in top form, too.
St. Louis set a season-high with 10 extra-base hits in a game that will stand as a measuring stick for both teams -- the Cardinals' most lopsided victory of the season, the Reds' worst home drubbing since a 16-7 loss to the Cubs on opening day.
"A lot of times after you score a lot of runs, the next day you can't find 'em," manager Tony La Russa said. "So enjoy the moment."
The two series against their closest pursuer present the Cardinals with a chance to take big steps toward their sixth division title in seven seasons. They don't play the Reds again the rest of the way.
The Reds know they have to at least keep up during the two series in order have a shot at catching the Cardinals down the stretch. Otherwise, they'll fall back into the dense pack of teams jostling for the NL wild card.
"They came out swinging," Reds outfielder Ryan Freel said. "Hopefully we can come out tomorrow and put on a better show than we did today. We've got to make adjustments and come out and do the opposite of what we did today."
Sensing the series' importance, the Reds tried to lure fans with offers of half-price tickets and $1 hot dogs for three of the series' four games. Crowds at Great American Ball Park have been a disappointment -- averaging under 27,000 -- despite the Reds' midseason moves to stay in playoff contention.
The cut-rate seats and dollar dogs attracted 34,262 fans on Monday, well short of a full house. A few hundred of them were still waiting in line for tickets outside the ballpark while the Cardinals pulled off their biggest first inning of the season -- five emphatic runs that showed who's in charge.
The first four batters piled up hits off Elizardo Ramirez (4-8), and Molina capped the rally with his fourth homer, a two-run shot. Duncan homered in the second off Ramirez, who matched his career high by giving up seven runs in only 1 2-3 innings.
The Cardinals didn't waste time against Ramirez, getting hits on four of his first eight pitches. They needed only a dozen pitches to pile up those five runs.
"Every time I threw a strike, they made contact," Ramirez said. "Base hit, base hit, base hit. I don't know what happened."
Molina's two-run double in the fourth off right-hander Ryan Franklin -- acquired earlier in the day from Philadelphia -- made it 9-1 and gave him four RBIs, matching his career high. Molina had been in a slump since the All-Star break, batting .175 with only six RBIs.
Spiezio's two-run homer in the ninth off David Weathers completed a 17-hit game by the Cardinals, two shy of their season high. The four homers matched their season high.
Notes: Molina also drove in four runs on May 25, 2005 against Pittsburgh. ... SS David Eckstein got the team's permission to stay back in St. Louis and attend to a personal matter. He's expected back for the second game of the series. Aaron Miles made his first start of the season at SS. ... In his four previous starts for St. Louis, Weaver gave up 18 earned runs in 18 1-3 innings. ... The Reds put RH reliever Gary Majewski (sore shoulder) and RH reliever Jason Standridge (sore back) on the 15-day DL before the game. They also activated LH reliever Kent Mercker.