St. Louis will try to build on that performance in Sunday's finale by continuing its recent success against former Cardinals right-hander Edwin Jackson.
St. Louis (6-5) batted .212 in its first 10 games and scored three runs or fewer in six of those contests. The Cardinals had seven hits in a 6-3 loss in 11 innings in Friday's series opener but blew out the Cubs 10-4 the next day.
All but one starter drove in at least one run, including pitcher Adam Wainwright, and Matt Adams' solo homer kicked off a four-run second inning. Jon Jay singled in two runs to complete a five-run fourth.
"It was nice to get some runs," manager Mike Matheny said. "We took some good at-bats right from the top."
The Cardinals, winners in six of their last seven against their rivals and five of six at home, will try to keep rolling versus Jackson (0-0, 6.30), who started 12 games in 2011 for St. Louis and four in the postseason for the World Series champions.
The right-hander is 1-5 with a 7.52 ERA in his last seven starts against the Cardinals, including a loss for Washington in Game 3 of the 2012 NL division series.
Jackson gave up two runs and two hits over 5 1-3 innings in his season debut, a 4-3 loss in 16 innings to Pittsburgh on April 2. He gave up four runs in the opening frame in a rematch with the Pirates on Tuesday and allowed six in 4 2-3 innings in a 7-6 loss.
"They came out aggressive and I left a lot of balls out over the plate, which is a bad combination," Jackson told the team's website. "I have to do a better job of getting the ball down and executing pitches, especially when your team comes back and gives you runs."
Yadier Molina is 12 for 23 (.522) lifetime against Jackson and Allen Craig is 7 for 15 (.467). They'll try to add to those hit totals while helping Michael Wacha (1-0, 0.71) win back-to-back starts.
The right-hander gave up one run over six innings Monday in his second of two matchups with Cincinnati to start this season, a 5-3 victory. He pitched 6 2-3 scoreless innings and struck out seven in his season debut April 2 but the Reds won 1-0.
Wacha did not get a decision in his only start against the Cubs on Aug. 10. He gave up two runs, five hits and three walks over five innings in that game.
Chicago's Emilio Bonifacio, 20 for 46 (.435) in his first 10 games, could return to the lineup Sunday after getting a break. He's 3 for 29 (.103) in his last seven games against the Cardinals and has never faced Wacha.
"When someone is as hot as he is, you'd love to have him in there all the time," manager Rick Renteria said. "We've played a lot of night games and extra-inning games, and he's on the bases a lot. Guys when they're on the bases a lot, there's a little wear and tear on the body. You want to be mindful of that."
Starlin Castro, batting .405 while hitting safely in eight of his last nine games, is hitting .386 in his last 15 against St. Louis and is 1 for 2 versus Wacha.