ST. LOUIS (Ticker) -- Brandon Backe and Pete Munro were not expected to keep the Houston Astros in the first two games of the National League Championship Series. Manager Phil Garner 's bullpen practically has pitched them out of it.

Albert Pujols and Scott Rolen belted back-to-back homers off Dan Miceli in the bottom of the eighth inning, lifting the St. Louis Cardinals to a 6-4 triumph over the Astros in Game Two of the NLCS.

In the series opener, Backe was replaced in the fifth inning with Houston holding a 4-3 lead. But Chad Qualls was unable to preserve the advantage, allowing five runs while recording just three outs as the Cardinals posted a 10-7 victory.

Making his first career postseason start in this one, Munro carried a 4-0 lead into the fifth before surrendering a two-run blast to Larry Walker . Pujols followed with a single, prompting Garner to call on Chad Harville , who gave up a three-run double to Jim Edmonds in Game One.

"He did a good job," Garner said of Munro, who allowed three runs and six hits in 4 2/3 innings. "He got us into the fifth and that's where we've had trouble. I thought we could get out of the fifth and still have the lead."

"I was throwing strikes, mixing it up well," Munro said. "In the fifth inning, I just was trying to do a little bit too much and I rushed a little bit, and that's when I started falling behind guys."

Harville again provided little relief, serving up a two-run shot to the slumping Rolen that gave St. Louis a 4-3 edge.

"I thought I made a decent pitch to Rolen and he hit it out of the yard," Harville said. "He got under it and he got it out of there. I wanted to try to get ahead 0-2 right there."

"We'll get it worked out," Garner said of Houston's bullpen woes. "Thank goodness this wasn't a two-game series. We're not really where we want to be, certainly, but we'll get it worked out. They'll come through for us."

Houston failed to capitalize on a singles by Jose Vizcaino and Brad Ausmus that opened the sixth, but Morgan Ensberg - who swatted his first career playoff homer in the fourth - plated Lance Berkman with a single in the seventh to draw the Astros even.

Miceli (0-2) replaced Dan Wheeler to start the eighth and was greeted by Pujols' fourth homer of the postseason, giving St. Louis a 5-4 advantage.

"It came at the right time," Pujols said. "Good pitch, you try for the best part of the bat. That's what happened tonight."

Rolen followed with his second of the game, marking the first time players have hit back-to-back homers in club postseason history. The All-Star third baseman also became the fourth Cardinal to belt two homers in a playoff game, joining Walker, Ron Gant and Willie McGee .

"It's a special honor," Rolen said. "I don't think we're out here for individual accolades, so to speak. The numbers that matter the most are 6-4 tonight."

"I just got a couple (pitches) up," Miceli said. "I was trying to make quality pitches away, trying to get ahead of them. A couple pitches got up and they hit them out."

Rolen did not allow the steady drizzle that fell throughout the game to affect his performance.

"The weather conditions weren't great," he said. "All night, they said it was going to quit raining. It never did. It picked up later in the game. ... When you're out there playing in a game like tonight, you kind of let the weather go."

"That's huge, like most of the season," Cardinals manager Tony La Russa said of Rolen's efforts. "Everybody got a chance to see he was so clutch all year long, and this is about as clutch as you can get."

The blasts made a winner of Julian Tavarez (1-0), who tossed a perfect eighth. Jason Isringhausen worked around a pair of walks in the ninth for his second save of the playoffs.

Trailing two games to none, the Astros return to Minute Maid Park for Game Three on Saturday, when Roger Clemens faces Jeff Suppan .

"You've got to put these two games behind us," Houston's Jeff Bagwell said. "We're not out of this thing by any means right now. We're going home, we've got our two big guys (Clemens and Roy Oswalt ) going for us, we've got our home crowd and we can do the exact same thing that happened here."

After rain delayed the start of the game for 46 minutes, Carlos Beltran gave Houston an early lead against Matt Morris , belting his sixth homer of the postseason and second of the series with one out in the first inning.

The Cardinals threatened to draw even in the bottom half as Tony Womack led off with a single and took second on a botched pickoff attempt. But Munro settled down, retiring the next six batters before Mike Matheny 's leadoff base hit in the third.

Morris followed with a sacrifice and a groundout by Womack moved Matheny to third, but Munro struck out Walker to maintain the lead.

Ensberg doubled the Astros' advantage in the fourth, depositing a 1-1 offering over the left field wall to open the frame. An inning later, Berkman made it 3-0 with a one-out single that plated Craig Biggio , who led off with a base hit and moved to second on a balk.

Munro struck out Matheny to start the bottom of the fifth but walked pinch hitter Marlon Anderson . Womack reached on a forceout and stole second before Walker golfed a 2-2 offering over the right field fence to draw the Cardinals within 3-2.

"I was just trying to stay back and hit a pitch," Walker said. "I thought it was a decent pitch. I just stayed back and whipped it, kind of, and turned on it."

"I thought Walker hit a good pitch," Munro said. "I was pitching well up to that point, but he gets paid to hit home runs. It was a changeup. I struck him out in the first at-bat with it."

Questioned for lifting Backe a day earlier, Garner turned to Harville after Pujols singled to center. But the move again backfired as Rolen smashed the reliever's second pitch over the left field wall for just his second hit in 17 at-bats.

"My third at-bat tonight, I was able to get a ball that I wouldn't stand back real well on," said Rolen, who ended an 0-for-12 slide with an RBI single on Wednesday. "I was able to take it, get the barrel on that ball and hit it out of the park. You build on that. You try to have a good approach and you try not to be result-oriented, but sometimes you need a little success for confidence to take over."

Steve Kline started the sixth in relief of Morris, who yielded three runs and six hits with five walks and five strikeouts, and gave up consecutive singles before La Russa brought in Kiko Calero .

Pinch hitter Eric Bruntlett failed to advance the runners with a sacrifice and Biggio struck out before Calero walked Beltran to load the bases. But Bagwell could not drive in the tying run, flying out to right field.

"He really can do a lot of things, pitch in a lot of different situations," La Russa said of Calero. "He's very good in the clutch."

The Astros did get to Calero in the seventh as Berkman opened the inning with a double and, one out later, stole third. Ensberg followed with a single to center to plate Berkman but was caught stealing before Vizcaino grounded out.

Wheeler, who retired six of the seven batters he faced in Game One, tossed two perfect innings in this one before being replaced by Miceli.