ST. LOUIS -- The Astros measured themselves against the National League's best team this weekend, and found themselves wanting. Chris Carpenter, on the other hand, measured himself against the man who may be the greatest pitcher since World War II, and came out of the comparison quite favorably for one day.

Carpenter, the best pitcher on the National League's top pitching staff, tossed his fourth shutout of the season, outdueling future Hall of Famer Roger Clemens in a 3-0 St. Louis win over Houston. Carpenter struck out nine Astros, allowed three hits and didn't issue a walk. It was more of the same for the Senior Circuit's All-Star Game starter, who hasn't allowed more than one run in any of his last six starts.

"Unfairly to him, we kind of expect him to go out and throw shutouts," said Scott Rolen, who contributed the game-winning hit. "And it's not that easy."

It just looks that way.

With the ninth shutout of his big-league career, Carpenter became the National League's first 14-game winner, and may have seized control of the Cy Young race as well. His 2.34 ERA ranks second to Clemens, his 137 strikeouts are second to Pedro Martinez, he's tied for the league lead in shutouts and he's second in innings pitched and complete games.

"He's pitched really well all year," said manager Tony La Russa. "I would say that location is [the key]. He's really getting the ball down quite a bit with movement.

"When he threw the ball inside today, he was right on the black with movement. He got ground balls to the left side. He's pitching to a very wide plate because he goes to the other side. His breaking ball is down with good break. He's locating very, very well with good stuff."

Carpenter's stuff, and his command, are all his own. But his preparation and his mental approach to the game owe a great deal to Clemens, who was his teammate for two years in Toronto.

"He is the most prepared and mentally strong pitcher I've ever seen pitch," Carpenter said. "He will not let up, ever. He's very strong mentally as a human being, and that's what makes him successful. He takes his day very seriously and doesn't give one away. That's why he's as successful as he's been.

"I learned a lot from him, watching him every day. You're stupid as a young kid not to pay attention to what someone of his caliber does. It was great to be able to play and watch him work."

Capped off by Clemens, the Astros -- who had been surging coming into the All-Star break -- sent their top three starters to the mound against St. Louis this weekend. Yet the Cardinals swept Houston, riding three brilliant pitching performances of their own.

Houston now finds itself in third place in the division, 14 1/2 games back, with only three head-to-head games remaining against the Cards. The Redbirds have taken 10 straight games from the 'Stros at Busch Stadium, including four in last season's National League Championship Series.

"Carp put the cap on it," La Russa said. "We pitched like that for three days and so did they."

The Cardinals took the series despite scoring a total of 11 runs in three games. For the second time in the series, all of St. Louis' runs came in one inning.

After Clemens breezed through the first four batters on nine pitches, Larry Walker earned a one-out walk in the second. Rolen fell behind 0-2, but fouled off four more pitches on his way to a 2-2 count. On the ninth pitch of the at-bat, the previously scuffling third baseman lined a ball to right-center and Willy Taveras couldn't track it down. Walker scored, and Carpenter had all the offense he needed.

"I finally got one over the plate and I was able to put the bat head on it, which I haven't done for a while," said Rolen.

So Taguchi beat out an infield single and Mike Mahoney walked, loading the bases for Carpenter. Once again Clemens got ahead 0-2, but Carpenter fought off a pitch and bounced it up the first-base line. First baseman Mike Lamb, finding a 6-foot-5 obstacle in the form of Carpenter in his way, fired a wide throw that allowed two runs to score.

Carpenter took over the game from there. After the third, he allowed just one hit, mixing a biting curveball with his power sinker and a tight cut fastball. Houston stacked up nearly every left-handed hitter it could, hoping to seize on an edge that no longer exists. Left-handers gave Carpenter trouble earlier this year, but no one is hitting him these days.

"The bottom line was that I wasn't executing quality pitches against some of the lefties," Carpenter said. "And when I start doing that, I get outs. It's all about execution and location, and it doesn't matter whether they're left-handed or right-handed."