ST. LOUIS -- There was a definite carryover effect from the opener of Thursday's day-night doubleheader to the nightcap.

Riding the wave of Matt Carpenter's walk-off grand slam that capped an 8-4, 11-inning decision in the first game, the St. Louis Cardinals jumped out to a 6-0 lead in the nightcap and hung on for a 6-4 win over the Toronto Blue Jays that finished a sweep.

St. Louis (11-11) rapped out 12 hits in the second game and scored all its runs in the first four innings. Leadoff man Dexter Fowler went 3-for-4 with a solo homer, scoring twice, and Matt Adams and Greg Garcia added three hits apiece. Adams knocked in two runs.

"That was a big, big win," Cardinals starter Adam Wainwright said of the opener in which his team trailed 4-0 going to the bottom of the seventh. "That gave us some momentum going into the second game."

Peppering rookie right-hander Casey Lawrence (0-3) in his second big league start during the night game, St. Louis established a 3-0 first-inning lead. Carpenter's infield out scored Fowler, Stephen Piscotty's sacrifice fly to deep center plated Garcia, and Adams laced the first of his two doubles into the left field corner to score Randal Grichuk.

Fowler made it 4-0 in the second with his third homer, a two-out shot to right center that caromed off the top of the wall and plopped into the front row.

Adams upped the lead to five an inning later when he lined an RBI single to left that nearly struck Piscotty, who was stealing third on the pitch and needed to swerve to avoid the ball. Piscotty capped the outburst in the fourth with a fielder's-choice grounder to short that scored Wainwright.

With Toronto's bullpen mostly used up from the opening game as manager John Gibbons called on six relievers, Lawrence had to work five innings even though he clearly didn't have the stuff or command to fool the Cardinals' hitters. Lawrence allowed 10 hits and six runs, walking three and fanning one.

"They hit me around pretty good," he said. "It didn't matter who was up there. I gave up 10 hits so they were swinging well. I just didn't make pitches and paid for it."

Meanwhile, Wainwright (2-3) enjoyed his longest outing of the year, weathering a four-run fifth to pick up his second straight victory. He lasted 6 1/3 innings, yielding nine hits and four runs while issuing a walk and whiffing four.

The Blue Jays (6-16) used Kevin Pillar's RBI infield single and a three-run homer to right by Kendrys Morales, his fourth of the year, to muscle their way back into contention. But Wainwright and three relievers teamed to retire 12 of the final 13 men they faced.

Trevor Rosenthal touched 102 mph with one fastball in the ninth, striking out two of his three hitters to post his second save.

"It feels real good to walk out of here with two wins," St. Louis manager Mike Matheny said. "I saw some positive things out there today. The guys kept putting pressure on their pitchers. We put up some good at-bats. Our offense should be able to score some runs."

Toronto was an out from its first series win and its first back-to-back wins in the opener. However, Grichuk sent those hopes sailing over the left-center-field wall, ripping Roberto Osuna's 94 mph fastball 412 feet with Yadier Molina aboard to force extra innings.

Carpenter's 403-foot blast into the seats in right field ended the 3-hour, 32-minute opener, and the Cardinals simply built on that in the nightcap.

"It can be a cruel game," Blue Jays manager John Gibbons said. "It would have been nice to get one of those games."

NOTES: St. Louis 1B Matt Carpenter's grand slam to end Thursday's opener was the team's first walk-off slam since Aaron Miles had one against San Diego in July 2008. It was the Cardinals' first walk-off, extra-inning slam since Tommy Herr victimized the New York Mets in 1987. ... Toronto RHP Roberto Osuna's blown save in the opener was his sixth in his past eight save chances, dating to September. ... Cardinals 2B Kolten Wong's intentional walk in the opener was his fourth of the season, tying him for the National League lead.