ST. LOUIS -- Sensing weakness from New York Mets starter Bartolo Colon, the St. Louis Cardinals wasted little time pouncing on him with a big inning, then kept adding on to their lead.

Right fielder Jason Heyward went 5-for-5 and center fielder Randal Grichuk cracked two homers Saturday night as St. Louis routed New York 12-2 at sold-out Busch Stadium.

Colon entered the game with only 11 walks in 105 innings, owning the second-best walk ratio in the majors behind Minnesota's Phil Hughes. But Colon issued a leadoff walk to second baseman Kolten Wong and things quickly went haywire for the 42-year old right hander.

Heyward followed shortstop Jhonny Peralta's RBI single with one of his own. Catcher Yadier Molina tacked on a ground-rule double to score Peralta, and Colon made it 4-0 when he plunked Grichuk after passing first baseman Mark Reynolds to fill the bases.

"He's the type of guy who has to get ahead in the count to be effective," Heyward said of Colon. "I thought guys just took what he gave them. Some singles, some doubles and (Grichuk) went deep twice. We were taking really good at-bats, getting pitches to hit."

Heyward finished his night in style, grounding a 1-2 pitch from reliever Alex Torres into left field in the bottom of the eighth for the second five-hit game of his career. Heyward's other five-hit performance came on Sept. 26, 2013, for Atlanta against Philadelphia.

The only negative occurred when Heyward departed for a pinch-runner after experiencing cramping throughout his body. While Heyward said he could have stayed in the game if it was closer, he required IVs and an ice bath after the game, leaving his status for Sunday's series finale uncertain.

There was no such equivocation about Grichuk's power bat. He greeted reliever Carlos Torres with a two-run opposite field shot into the Cardinals' bullpen in the fifth for an 8-0 advantage, then capped the scoring in the eighth by walloping a three-run homer to left-center to become the first St. Louis rookie since David Freese in 2010 to drive in six runs in a game.

Heyward harkened back to his Atlanta days when asked if Grichuk's second two-homer game of the year overshadowed his five hits.

"I hit two homers one night and got overshadowed," Heyward joked. "Chipper (Jones) went 5-for-5."

Colon (9-8) was ripped for eight hits and seven runs in 4 1/3 innings, walking three and fanning five as his earned run average soared to 4.86.

"When he doesn't command the fastball," Mets manager Terry Collins said of Colon, "he's not the kind of guy who is going to go strictly off-speed. He just doesn't pitch like that, and tonight, he didn't have the command."

The Cardinals' 15-hit attack was far more than starter John Lackey (8-5) needed in his seventh straight quality start. Lackey scattered 10 hits over seven innings and allowed just one run on a leadoff homer in the sixth by left fielder Michael Cuddyer, giving up a walk and whiffing three.

St. Louis (58-33) improved to 33-11 at home and upped its National League Central lead to 4 1/2 games over Pittsburgh, an 8-5 loser in Milwaukee. New York (47-44) dropped to 15-30 on the road and fell three games behind first place Washington in the NL East.

It was an easy night for Cardinals skipper Mike Matheny, whose team normally wins its games with pitching and defense.

"Overall, the story today is the offense," he said. "It's always nice for your starters when you get a little offense going and give them some breathing room. John gave up some hits but he managed them well."

NOTES: St. Louis RHP Jordan Walden (right biceps) threw a bullpen session on Saturday as he attempts to return from an injury that has sidelined him since April 30. Walden was 0-1 with a 0.87 ERA in 12 appearances before the injury. ... New York starting pitchers entered Saturday with baseball's highest first-strike percentage at 66. The league average is 61.4. ... Cardinals LHP Jaime Garcia (groin) also threw a bullpen session Saturday. The team hopes he can progress to throwing live batting practice on Thursday and possibly rejoin the rotation before the end of the month.