CINCINNATI (AP) -As Javier Valentin dug in, representing the Cincinnati Reds ' final chance to score a run, right-hander Braden Looper felt a little pressure and started second-guessing himself for the first time all night.

What should he throw next?

The St. Louis Cardinals' reliever-turned-starter made the right choices and threw to the right spots, finishing off his first career shutout Wednesday night, 10-0 over the Cincinnati Reds .

Rick Ankiel and Jason LaRue homered in the first inning off wild Johnny Cueto , putting the Cardinals in control right away. The rest was up to Looper, who hadn't gone more than 8 1-3 innings in any of his 43 career starts.

He yelled in celebration when Valentin lofted a harmless fly ball for the final out.

''It's an achievement I can look back on and always have,'' Looper said. ''Obviously it's not a no-hitter, but I only gave up three hits in a nine-inning shutout. That's pretty good, I'd say.''

The Cardinals were pretty good all around.

Ankiel, LaRue and Ryan Ludwick homered for the Cardinals, who moved a season-high 13 games over .500 with their fourth straight win. The 10-run margin matched their biggest of the season.

Looper stayed in his up-and-down pattern, alternating losses and wins in his last six starts. The Reds got only two runners into scoring position against Looper, who didn't walk a batter and needed only 98 pitches.

''It was a good, solid game, but the guy that deserves most of the credit is the pitcher,'' manager Tony La Russa said. ''He set the tone.''

The last-place Reds did a little bit of everything wrong in their most lopsided loss of the season. Even impressive rookie Jay Bruce dropped a fly ball for his first error, letting in a run.

Cueto (5-6) couldn't get his pitches over the plate. He walked eight in only five innings, the most by a Reds pitcher since left-hander Steve Avery walked nine Diamondbacks on June 29, 1999.

''He just didn't have a good ballgame,'' catcher Paul Bako said. ''It was 5-0 before we came to bat. He gave us some innings later but the way Looper was throwing, it didn't matter.''

The Cardinals have kept winning - 10 of their last 13 - despite injuries that thinned the rotation and the lineup. They got their latest bad news on Wednesday: Albert Pujols will be out for at least three weeks with a strained left calf.

''Since day one, we've had guys who are part of the core of this club not participating, but the games still count and we're still playing,'' La Russa said.

With their top hitter gone, the Cardinals carried on.

''You know what? You can't control what happens,'' LaRue said. ''It's a big hit (losing Pujols), but this team is capable of winning without him.''

The Reds have been much like Cueto, a 22-year-old rookie who impresses at times and falls apart at many others. He'll either dominate hitters with a well-placed 94 mph fastball, or leave it down the middle. The Cardinals made him look like a rookie for the second time this season.

They provided his previous worst moment in the majors on April 29, scoring seven runs in a 7-2 win. Cueto managed to retire only five batters before his quickest-ever exit.

Not a whole lot better this time around.

''He's thrown the ball well for a guy his age outside of tonight and one other game,'' manager Dusty Baker said. ''He started missing, then he started to overthrow.''

St. Louis had three walks and a pair of homers in the first inning. Ankiel hit a three-run homer, his second in two games since returning from a knee infection. LaRue added a two-run shot, his first homer since July 31.

Cueto kept himself in constant trouble with the eight walks, the most by a Reds right-hander since Bruce Berenyi walked eight Giants on April 17, 1982.

Ludwick doubled home a run in the fourth for a 6-0 lead and later added his career-high 16th homer, his second in two games, as the Cardinals pulled away.

Notes: RHP Adam Wainwright went on the DL with a sprained finger on his pitching hand. The Cardinals are expected to put Pujols on the DL on Thursday and activate pitcher Joel Pineiro , who will start the final game of the series. ... LHP Mark Mulder will begin a rehab assignment Saturday with Double-A Springfield. Mulder has been trying to come back from shoulder surgery. ... Cueto has given up at least one homer in 11 of his 14 starts. ... Jolbert Cabrera started at 2B for the Reds, who gave Brandon Phillips a day of rest. It was Cabrera's first appearance in the majors since Oct. 3, 2004 for Seattle.