ST. LOUIS -- St. Louis Cardinals manager Mike Matheny believes Kyle Lohse belongs in the NL Cy Young conversation.

Helping the World Series champions get to the postseason will do for now.

The right-hander threw seven scoreless innings for his 15th victory and contributed an RBI double as the Cardinals beat the Houston Astros 4-1 Tuesday night to stay in front for the second NL wild card.

"He was in position to have many more wins than 15 right now," Matheny said. "He's thriving on being that guy for us, to really set the bar for the rest of the starters.

"If we would have been able to hold some of the leads that he had, there's no question he'd be right at the top of that mix," Matheny added.

Fernando Abad (0-5) had a career-best six strikeouts in the Astros' 100th loss. They're 8-8 this month under interim manager Tony DeFrancesco and need nine wins in the final 14 games to avoid topping last season's franchise-record 106 losses.

DeFrancesco is hindered by a roster filled with prospects.

"When I got the job it was already where it was at," DeFrancesco said. "We know what's on the field. We know what direction the team is going, and we're excited about our future."

Excited about Wednesday, too.

"We know what's on their mind over there, to get that second wild-card spot," cleanup man Justin Maxwell said. "If we can do our job and win games, we can definitely be the spoilers."

Daniel Descalso got a key early RBI and Jon Jay had two hits and two RBI for the Cardinals, coming off a 2-5 trip. But they have a favorable upcoming schedule with the next eight against lowly Houston and Chicago. With 14 games to play, the defending World Series champions are 1½ games ahead of the Dodgers, rained out at Washington, and 2½ games ahead of the Brewers.

Lohse (15-3) matched his season best for victories set in 2008 with St. Louis, on his fourth attempt while stranding two runners in the third and seventh. A .281 career hitter entering the season, he raised his average this year to .100 with his third RBI on a bouncer over drawn-in third baseman Matt Dominguez.

It was hit first extra-base hit since a double Sept. 19, 2011, at Philadelphia off Roy Halladay.

"That looked like a Hall of Fame swing, didn't it?" Lohse joked. "It says .100 up there and I'm just glad it's there instead of lower.

"A positive thing is when it's in the 80s it doesn't go down much every time you make an out."

Due for free agency after the season, Lohse leads the majors with a winning percentage of .833 and is among the National League leaders with a 2.71 ERA.

"It's easy to just concentrate on what I'm doing," Lohse said. "I try to take that focus every fifth day. If I'm worried about numbers, what could have been, or ... contracts, none of that matters to me."

Abad allowed three runs in five innings, the longest of his five career starts -- all this year -- and is 1-10 with a 5.12 ERA in parts of three seasons with Houston. Brett Wallace had an RBI single off Mitchell Boggs in the eighth.

The Cardinals had four extra-base hits, three of them in succession with one out in the fifth. Pete Kozma tripled, Lohse doubled and Jay doubled to make it 3-0.

They missed a chance for more when Carlos Beltran struck out and Jay was thrown out at third. It was the second time one of St. Louis' best hitters whiffed in the clutch and Astros catcher Jason Castro turned it into a double play. Matt Holliday struck out and Jay was thrown out at second to end the first.

Yadier Molina singled with one out in the second and scored on a two-out single by Descalso, who had been batting just .104 with runners in scoring position (8 for 77) on the year and was 1 for 16 on the trip. Descalso batted .294 with runners in scoring position as a rookie.

"We saw last year that guy can produce in those situations," Matheny said. "It's just a matter of trusting himself, getting a couple to fall in for in for him and hopefully he goes on a tear."

Jason Motte worked the ninth for his 36th save in 43 chances.

Notes

• RHP Chris Carpenter threw in the bullpen and remained on track to make his first start of the season Friday at Chicago. Carpenter underwent surgery to relieve nerve compression in his shoulder in late July and at that time had been hopeful of pitching next year in the final year of a two-year contract.
• Lance Lynn (15-7, 3.95) faces Lucas Harrell (10-9, 3.86) in the second game of the three-game series Wednesday night.
• Rams DE Robert Quinn threw out a ceremonial first pitch.
• RHP Jake Westbrook, who has missed one start with pulled side muscle, played catch Monday and could return well before the end of the regular season.
• Lohse is 10-8 against Houston and has not allowed more than three runs in any of his 18 career starts against the Astros.
• The Cardinals are 28-17 against left-handed starters.