HOUSTON -- What you might call midseason form, if you were talking about another player, is just Astros form for Jim Edmonds. On Tuesday night, the Cardinals' center fielder did what he always seems to do against Houston, hitting a three-run homer and driving in four runs in a 7-3 win.

It's old hat for Edmonds, who's been breaking the hearts of the Astros and their fans since his arrival in the National League in 2000. Last year's National League Championship Series brought his habits into national focus, but the beat has been going on for years. Houston manager Phil Garner won't even say Edmonds' name, calling him "the center fielder" or "that guy."

Meanwhile, as Edmonds was picking up where he left off in the 2004 NLCS, Chris Carpenter showed what he might have done if he'd had the opportunity to participate in the '04 postseason. Carpenter, who missed the playoffs last year due to a nerve injury in his right arm, held the new-look Astros to a run on four hits over seven innings in one of the senior circuit's toughest pitching environments.

Carpenter was smothering if not dominating in his second career Opening Day start. The right-hander struck out two and did not allow a walk, inducing 14 groundball outs against five in the air -- with three of the aerial outs coming in his final inning. Carpenter made it through seven frames on a tidy 97 pitches.

Of course, it helped that Carpenter had Edmonds on his side. With two on and two out in the top of the first, Edmonds worked a 3-2 count against 20-game winner Roy Oswalt. On the seventh pitch of the at-bat, he looped a liner to the opposite field and into the Crawford Boxes above the left-field fence for a 3-0 lead. Oswalt made a decent pitch, forcing Edmonds to lunge over the plate, but the end result was, in the words of David Byrne, "same as it ever was." Home run, Edmonds.

"[It was a] 3-2 curveball down and away where I wanted it," said Oswalt. "I figured he was going to try to pull the ball or settle on a fastball there, and kind of be out in front of it. He reached out over the plate and hit it. I didn't think it was going out when he first hit it, but it had good carry on it."

It was Edmonds' walk-off homer that forced Game 7 in last year's NLCS, and his catch in the seventh game was a key moment in the Redbirds' win. The seven-time Gold Glover also walked and hit a sac fly on Tuesday, though at least he spared the Astros and their 43,567 fans in attendance from one of his signature spectacular grabs.

"I didn't think anything," Edmonds said of his 303rd career home run. "I was just hitting and running."

Reggie Sanders added a two-run homer off Oswalt, and Larry Walker hit a solo shot against reliever Russ Springer in the seventh. The Cardinals have won three of their past four openers, but had lost the last three times they started the season on the road.

Even though Edmonds' play was huge, Carpenter's contributions were significant. Carpenter gave the Redbirds their best Opening Day start since Matt Morris in 2002, which coincidentally was the only other year in which Carpenter (while with Toronto) started the opener.

"It really did feel like another game to me today," said Carpenter. "Once I stepped out on the mound to start warming up, my nerves settled, my legs came back and I felt good. And that's a typical day for me. I'm nervous in the morning, and I get to the field, start preparing myself and thinking about what I want to do, and my mind settles down. My body settles down. I go out and start working."

Still, while the win showed off some of the Cards' returning strengths -- power, slick defense and Carpenter, as fine a relatively unknown pitcher as you'll find -- it also exposed one potential question mark. Despite taking a six-run lead into the eighth, St. Louis was forced to use all three of its top relievers over the final two innings.

Al Reyes, who along with Cal Eldred will try to fill the role left vacant by Kiko Calero's trade to Oakland, was touched for two runs in 2/3 inning. That led Cardinals manager Tony La Russa to call on Julian Tavarez, who walked Jeff Bagwell before striking out Morgan Ensberg to escape with runners on the corners.

La Russa tapped Ray King, his other primary setup man, to start the ninth, but King allowed consecutive two-out baserunners. Thus, what was a rout in the eighth turned into a save situation in the ninth, and Jason Isringhausen was credited with rescue No. 1 on the season. Houston actually brought the tying run to the plate in the ninth.

"Unfortunately, I set [Isringhausen] up for a one-out save," quipped King.

It was far from disaster, but if you're looking for warning signs, using four pitchers to get six outs in a game like Tuesday's might count as one.

"I don't call it a struggle," La Russa said. "Everybody came in there and got the first out or two, which is normally the first thing you want from the bullpen. Sometimes you've got to give the other side credit. And I do."