HOUSTON -- Tino Martinez is at his best in clutch situations.
Martinez hit a two-run homer off Roy Oswalt in the eighth inning to lift the St. Louis Cardinals to a 4-3 victory over the Houston Astros on Monday.
"The tougher the at-bat the more he concentrates and the better he is," Cardinals manager Tony La Russa said. "His at-bats have been getting better and better. The way he's been hitting the ball his average should be over .250."
Martinez got off to a terrible start this year after coming over from the New York Yankees as a free agent in the offseason, and he's still batting just .233. But Martinez has been coming on lately.
"I'm getting my swing and my mechanics down. I'm getting more relaxed and it's helping that I'm seeing the National League pitchers a second and third time," he said.
The Cardinals won for the eighth time in nine games and improved to 8-2 against Houston this season.
"It's not something that I want to make a whole lot out of. We still have to play them a lot more," La Russa said.
Lance Berkman homered twice for the Astros, including a two-run drive in the eighth that pulled Houston to 4-3. He has 17 home runs this year.
Gene Stechschulte (6-1) got the win despite giving up two runs in 1 1-3 innings, and Dave Veres got the last two outs in the eighth.
Jason Isringhausen got three outs for his 14th save in 15 chances, retiring Craig Biggio on a groundout with runners at second and third to end it. Isringhausen has saves in 10 of his last 11 outings.
Oswalt (5-3) gave up four runs and nine hits in 7 1-3 innings. He struck out four and walked one.
"I left the ball up for Tino's home run. My job is to keep us close and that is not keeping us close. I put everything on me. If I had gotten us out of that inning behind just 2-1, then we would have won," Oswalt said.
Martinez's home run was the first allowed by Oswalt in 63 1-3 innings since Colorado's Larry Walker went deep April 8 at Coors Field.
"They have things going their way right now," Houston's Daryle Ward said of the Cardinals. "They are winning and we are not. It's just one of those things. Breaks are going against us and we have to defeat all of the odds right now."
With the score tied at 1, Placido Polanco led off the eighth with a single for the Cardinals and moved to third on a single by Albert Pujols. Jim Edmonds drove in Polanco with a sacrifice fly before Martinez connected for his sixth home run of the season.
Biggio walked ahead of Berkman's home run off Stechschulte in the bottom half.
St. Louis starter Darryl Kile got his second straight no-decision against his former team, going six innings and giving up one run on eight hits. He struck out four and walked one.
"I thought that was the best stuff that Darryl has had all season," St. Louis catcher Mike Matheny said. "He was hitting his spots and throwing all of his pitches for strikes."
The Cardinals took a 1-0 lead in the fourth inning after consecutive singles by Polanco, Edmonds and Martinez loaded the bases with one out. Edgar Renteria drove in Polanco with a sacrifice fly.
Berkman homered leading off the sixth.
Houston had two runners on in the fourth and fifth, but both innings ended on double plays.
"The big key was Darryl Kile," La Russa said. "He was really at his best."