St. Louis ? Larry Walker needed three extra at-bats to get his postseason cycle.

The newest addition to St. Louis’ power-packed lineup hit a two-run homer off Pete Munro in the fifth inning of the Cardinals’ 6-4 victory over the Houston Astros in Game 2 of the NL championship series Thursday night.

In Game 1, Walker fell a home run shy of becoming the first player in major-league history to hit for the cycle in the postseason. He struck out in his last at-bat Wednesday and fanned in his first two plate appearances in Game 2 before jump-starting St. Louis’ slumbering offense.

“The first two times I struck out, and then I hit a home run, so the third one was way different,” Walker said. “I just tried to stay back and hit a pitch, and I was able to lift it.”

The Cardinals had been 0-for-7 with runners in scoring position against Munro, making his first career playoff start, before Walker connected for his third homer of the postseason. St. Louis received two homers from Scott Rolen and a go-ahead shot from Albert Pujols in the eighth inning to take a 2-0 lead in the best-of-seven series — with Houston aces Roger Clemens and Roy Oswalt scheduled to start Games 3 and 4.

“Well, it’s what we wanted to do,” Walker said. “Obviously, having the home-field advantage and now having a 2-0 lead is big when you got to go against Clemens and Oswalt.”

St. Louis' Larry Walker (33) accepts congratulations from teammates Tony Womack and Albert Pujols after hitting a two-run home run. The Cardinals defeated Houston, 6-4, Thursday night in St. Louis to take a 2-0 lead in the NL championship series.

Walker was more impressed with Pujols’ homer than his contribution. Pujols has a franchise-record four postseason homers.

“Albert’s a freak,” he said. “It’s amazing what he does there. I’ve only been here a couple of months, and it’s fun to watch. I can’t wait to see it some more.”

As for himself, he declined a curtain call because the Cardinals were trailing 3-2 after his homer. But he was impressed with the way a sellout crowd chanted his name.

“I think if you do half-decent, they like you,” Walker said. “Fortunately, I’ve been able to do half-decent.”