ST. LOUIS -- The big contract Kyle Lohse got from the St. Louis Cardinals has not gone to his head.

Lohse threw a career-best three-hitter, retiring 24 in a row after giving up a single on his first pitch, and St. Louis beat the Houston Astros 3-0 Sunday to complete a three-game sweep.

The right-hander is 2-0 with a 1.13 ERA, living up to the four-year, $41 million deal he got last September.

"I try not to think about it like that," Lohse said. "I'm privileged that they thought that much of me to give me a four-year deal. That's part of the job, to go out there and be professional about it, get your work done even when no one's looking."

Lohse is 17-6 since coming to St. Louis as a free agent last year. The latest victory evened his career mark at 80-80.

"He was masterful," manager Tony La Russa said. "Kyle signs a deal, and he wants to show he's going to be the same guy."

Khalil Greene had three hits and an RBI, and Ryan Ludwick extended his hitting streak to 16 games with an RBI single for the Cardinals, who went 5-2 on their opening homestand and limited the opposition to two or fewer runs in three of the last four. St. Louis outscored the Astros 19-5 in the three games.

"We hit probably two or three balls hard all day, and that won't get it," manager Cecil Cooper said. "We know we're a better offensive team than we have shown."

Kaz Matsui lined an opposite-field single to start the game for the Astros, who didn't get another baserunner until Michael Bourn singled leading off the ninth. Hunter Pence added a two-out hit and Lohse fell behind 3-0 against Lance Berkman before getting him to fly out.

Houston has lost four in a row and has scuffled to a 1-5 start while totaling 16 runs. The Astros were shut out for the first time since Sept. 14, 2008, when they were no-hit by Cubs ace Carlos Zambrano in a game moved from Houston to Milwaukee due to Hurricane Ike.

"It's just annoying," Geoff Blum said after going 0-for-3. "We shouldn't be losing games 3-0 with our lineup."

Lohse (2-0) threw his fifth career shutout, and first since May 28, 2007, against Pittsburgh while he was with the Reds. The complete game was his seventh, and first since July 6, 2007, against Arizona. His previous low-hit game had been a pair of four-hitters, the last also against the Diamondbacks.

Lohse, who struck out four and walked none, helped himself with an outstanding fielding play to rob Miguel Tejada of a bunt single leading off the fifth. Second baseman Skip Schumaker nearly topped that the next at-bat, making a leaping grab of Blum's liner.

Over the last two years, Lohse is 4-0 with a 1.91 ERA against the Astros in five starts. The foursome of Blum, Carlos Lee, Pence and Ivan Rodriguez was 1-for-12 after entering the game combining for a .378 average, most of it built before Lohse came to St. Louis.

"Yeah, I know their numbers," Lohse said. "I feel like I've got a better approach now and they're seeing some different stuff now."

Ludwick had an RBI single off Wandy Rodriguez (0-1) and Chris Duncan had a run-scoring groundout in the fourth to put the Cardinals ahead 2-0. Greene's two-out RBI single made it 3-0 in the fifth.

Rodriguez had a 1.11 ERA against the Cardinals last year in four starts, although he was 1-2. He's 2-7 with a 4.12 ERA for his career against St. Louis.

Notes

• Matsui and Bourn have hit in all six games to start the season.
• Rick Ankiel, 0-for-9 against Rodriguez, was the odd man out in the Cardinals' four-man outfield rotation.
• The Cardinals swept the Astros for the first time since taking three in a row from July 15-17, 2005, in St. Louis.
• CF Colby Rasmus collided with RF Ludwick after catching Pence's fly ball to start the seventh but neither player was hurt.
• Cardinals starters have a 14-inning scoreless streak.