ST. LOUIS -- If ever a non-elimination game could be pegged as a must-win one, Monday's Game 2 of the National League Division Series set up to be just that for the Cardinals.

Facing the prospect of falling behind, 0-2, in the best-of-five series, the Cards no longer have to worry about climbing out of a hole that no NL team has emerged from in DS history. Rather, the Nationals and Cardinals head to Washington all even, as the Redbirds overcame an injury to their own starter by ambushing Jordan Zimmermann to run away with a 12-4 victory in front of 45,840 at Busch Stadium.

"We wanted to come out and make a statement and tie this up before we went to D.C.," said Daniel Descalso, who contributed a two-hit, two-RBI day. "We came out and did exactly what we wanted to today."

Neither Zimmermann nor Cardinals starter Jaime Garcia lasted long in this one, though manager Mike Matheny's decision to yank Garcia after two innings was due entirely to necessity. The lefty labored through two innings, threw 51 pitches and went to a 3-2 count against five of the 11 batters he faced.

Garcia left the mound trailing, 1-0, in the second and made his way to Matheny, notifying his manager that his left shoulder -- the same one he injured earlier in the season -- wasn't feeling right and hadn't been since he threw a side session on Friday.

"It just didn't feel right," Garcia said shortly after undergoing an MRI exam. "It was hurting and wasn't feeling the way it has been the last couple of weeks."

Results of the MRI are expected back on Tuesday.

With Garcia out, Lance Lynn was summoned to step in. The Cardinals' offense ensured he was welcomed with a lead.

Facing a pitcher they have had sustained success against, the Cards scored four times off Zimmermann to take a second-inning lead. Singles by Allen Craig and Yadier Molina started the stirring. David Freese drove home the tying run with a double, and Descalso followed with an RBI single.

A productive out by pinch-hitter Skip Schumaker extended the lead, after which Jon Jay drove home one more with a two-out single. Zimmermann lasted only any inning longer, and Craig tagged him for a solo homer before his exit.

"They have a great lineup. It's tough," Zimmermann said. "You get a few guys out, then you look up and you've got [Carlos] Beltran coming up, Freese. It just never stops. Their lineup, you just have to make your pitches, and I wasn't able to do that tonight."

"That's some of the youth in the pitching staff," added Nats manager Davey Johnson. "He didn't really make a lot of adjustments out there."

The three-inning outing was the shortest of Zimmermann's 83-start career. He'd gladly not face the Cardinals again for a while, either. In six career outings against St. Louis, Zimmermann has allowed at least five runs in five of them.

"He's a good pitcher, but anything can happen in this game in these short series," Beltran said. "We felt that we were able to get to him early. He was flipping fastballs early in the count, and we were swinging the bats and finding holes."

Craig's homer was the first of four blasts the Cards used to pad their lead. Descalso, who hit only four regular-season home runs, connected for solo one off reliever Craig Stammen in the fourth.

Beltran then tattooed a Mike Gonzalez changeup in the sixth to extend the Cardinals' lead to 8-3. Two innings later, he belted a two-run homer to give him his second multihomer performance in an NLDS game. Beltran also accomplished the feat in 2004, when he was with Houston.

An offense that tallied only nine hits in its first two postseason games had that total matched by the end of seven innings on Monday. St. Louis finished with 13.

"We know this offense has the potential to do this," Matheny said. "It was nice to see this, and hopefully it becomes contagious and the guys just keep going."

As the offense clicked, Lynn cruised. Asked to carry the games through the middle innings, Lynn -- moved to the bullpen only because of Chris Carpenter's recent return to the rotation -- gave the Cards three innings in relief. He was stung only by back-to-back solo homers in the fifth.

"Lance stepped up in big fashion and was able to really take advantage of the opportunity," Matheny said. "We needed him badly."

The right-hander struck out five in an outing that could be his last one in relief for a while. Should the Cardinals advance and Garcia remain sidelined, Lynn, an 18-game winner during the regular season, would likely slide back into the rotation.

"[I] did everything I could to get as many innings as possible," Lynn said. "It worked out well for us."

Joe Kelly covered the sixth with assistance from Jay, who made a tremendous running catch to save a leadoff extra-base hit by Danny Espinosa. Best catch of the year, Jay labeled it afterward.

Jay also finished with a three-RBI performance at the plate. He drove in two of those runs with two outs.

Edward Mujica, Mitchell Boggs and Trevor Rosenthal took care of the final three innings for St. Louis, allowing closer Jason Motte to get a night off.

With the victory, the Cardinals have ensured themselves of at least two more games. And with Chris Carpenter and Kyle Lohse lined up to start Games 3 and 4, the Cards, despite playing the rest of the series on the road, hardly feel at a disadvantage.

"It was big. ... We knew how big this game was for us," Jay said. "That's the type of offense we have. We've seen it all year -- when we are able to [take good at-bats], we are pretty dangerous. It worked out today."