ST. LOUIS -- The Houston Astros who still remain after a housecleaning are playing as if they're contenders.

Jeff Keppinger had two hits and matched his season-best with four RBIs, including a key hit during a go-ahead three-run eighth inning, and the Astros won their sixth straight to spoil Jake Westbrook's St. Louis debut with a 9-4 victory over the Cardinals on Monday night.

Houston did it without pitching ace Roy Oswalt and slugger Lance Berkman, who are playing elsewhere these days after trades last week.

"It seems like we've got a whole new team," Kepppinger said. "We've got a lot of young guys up here trying to prove themselves, prove they belong, and they're coming through."

Albert Pujols homered for the third straight game and Westbrook worked six strong innings for St. Louis, which lost for only the second time in 13 home games. The Cardinals have lost four straight at home to Houston, falling a half-game behind the Reds in the NL Central.

Cardinals starting pitcher Jake Westbrook throws to an Astros batter during the second inning Monday in St. Louis. Westbrook was making his Cardinals debut after being acquired Saturday in a trade with the Cleveland Indians. (Jeff Roberson) ~ Associated Press)

Brett Myers extended his franchise-best streak to 22 consecutive starts of six or more innings to begin the season. Keppinger's RBI double off Mike MacDougal (1-1) tied it at 4-4, and Carlos Lee scored the go-ahead run by beating a wide throw home from second baseman Skip Schumaker on Chris Johnson's bases-loaded chopper.

"Finally we're getting some big hits with people on base," Lee said. "I'm telling you, the last I would say 10 games there's been a lot of excitement. It's difficult to see teammates traded but I think that sent a message to the team, and now we don't rely on nobody."

Keppinger added a two-run single in a four-run ninth as the Astros batted around against Trever Miller and Blake Hawks-worth. Keppinger is batting .433 (13 for 30) with a homer and 11 of his 40 RBIs against the Cardinals this season.

"Sick," Keppinger joked. "I guess I've got guys in front of me getting on base, giving me opportunities to drive in runs, and fortunately I've been coming through."

Nelson Figueroa (3-1) allowed an RBI double by Felipe Lopez that put the Cardinals ahead 4-2 in the seventh, but Jason Motte walked Michael Bourn and Anderson Hernandez on 10 pitches to open the eighth, and both scored.

The Cardinals' Albert Pujols watches his solo home during the fourth inning. The blast was Pujols' 26th of the season and third in three games.

"Second inning, I had no clue where the ball was going," Motte said. "Everything was just all over the place."

Pujols tied it at 2-2, leading off the third with a liner into the visitors' bullpen in left for his 26th homer of the season and the 392nd of his career, the most in a player's first 10 seasons in major league history. He has three homers and 11 RBIs against the Astros this season, and is a career .366 hitter against Myers with three homers and 11 RBIs.

Myers said Pujols hit a fastball that was supposed to be inside and drifted over the plate.

"He's supposed to hit pitches like that," Myers said. "When I let it go I said, 'He's going to kill it,' and he did."

Westbrook made his first start in a week and had seven strikeouts, one off his season best, and kept the ball down to limit Houston to one flyball out. The Cardinals acquired Westbrook for outfielder Ryan Ludwick in a three-way deal with the Indians and Padres.

"A little nervous, a little excited," Westbrook said. "But I felt like I was able to harness those feelings and settle in."

Rookie Brett Wallace, who was the Cardinals' first-round draft pick in 2008, lined a single off Westbrook's leg for his first RBI against his old team. Working with a one-run lead, Westbrook struck out Wallace with two men on to end the sixth.

The Astros survived throwing errors in the first by Myers and Bourn in center field while falling behind 1-0. Keppinger was charged with a third error when he couldn't get his glove on a grounder by Lopez leading off the inning, but the call was changed to a hit an inning later.

"That was fun," Myers said. "But I was able to work around and ultimately we won, so that's all that matters."