ST. LOUIS — Behind Adam Wainwright, the St. Louis Cardinals stayed on the fast track Tuesday.
Wainwright (12-5) allowed one run on five hits and struck out nine in seven innings as the Cardinals whipped Houston 9-5 and increased their first-place lead in the NL Central to 1 1/2 games over Pittsburgh.
It was the Cardinals' fourth straight win since they suffered a crushing 6-5 loss to the Los Angeles Angels on Thursday.
"It's important. Any game is important," Wainwright said. "We had a tough stretch there for a minute, so it's good to get back on track.
"No excuses, but we've had a very tough schedule. We've had a lot of road games --four 10-day road trips, if I'm not mistaken. That wears you out. What you saw about a week ago was probably a little fatigue for the team.
"We want to finish up strong and get that good (All-Star) break and get ready for the second half."
Wainwright, using his patented curveball, improved to 13-1 with a 1.57 ERA in his career against Houston.
"It was good," Wainwright said of his breaking ball. "I felt it coming off the fingers good tonight and I was able to change speed with it --some hard, some slow. It's just another way to vary your pitches."
Wainwright has little explanation for his domination against the Astros.
"I don't know, man," he said. "It's just one of those weird things. I've matched up well with them over the years."
Johnson back in bigs
Catcher Rob Johnson, who replaced the released Ty Wigginton on the roster Tuesday, earned the Cardinals' respect in spring training with the way he handled their pitching staff.
"I take a lot of pride in that," said Johnson, 30, who signed a minor-league deal with the Cardinals in November. "I take a lot of pride in game-calling, what I try to do behind the plate and getting on the same page as pitchers, just talking to guys about what it's like to be up here. A lot of guys have been very receptive."
Johnson is glad he made enough of an impact to earn another chance in the big leagues.
"That's exactly what it is: It's an opportunity to come up," Johnson said. "I've never been on a team that's in first place in the big leagues. It's a good opportunity (with) a bunch of good guys. I'm excited to be here and help and contribute any way I can.
"It kind of caught me off-guard, for sure. I didn't expect it at all, but now that I'm here, I'm locked in and ready to go."
Johnson said he learned about the promotion at 7:30 a.m. Monday when he ran into Memphis manager Ron "Pop" Warner.
"I saw Pop on the street when I was coming back from breakfast," Johnson said. "It was real exciting. You can never take it for granted because you never know when you will get back up here again."
Johnson was batting .236 with seven home runs and 32 RBIs in 59 games at Class AAA Memphis. He is a career .201 hitter with eight homers in 245 games and 791 at-bats in the big leagues with Seattle, San Diego and the New York Mets.
"I've actually really enjoyed this season," Johnson said. "There's been a lot of good stuff going on down there for the Triple-A club. There's a lot of really good ballplayers, guys learning, guys getting better. We've got some great arms down there."
Chris Carpenter will throw a simulated game against hitters Wednesday, and General Manager John Mozeliak expects him to eclipse the 100-pitch mark.
"The key there is if all goes well, the next outing would be on the clock," Mozeliak said, referring to a rehab assignment that is drawing closer and closer.
If all goes well Wednesday, Carpenter would his next simulated game in Jupiter, Fla. The next step would be a rehab assignment.
Rookie left-hander Kevin Siegrist worked a perfect eighth inning Tuesday, recording his 12th consecutive scoreless appearance.
That sets a franchise record previously held by Tyler Johnson, who had 11 straight scoreless outings in 2005-06. Johnson's streak, however, covered just 5 1/3 innings. Siegrist has thrown 12 innings.
Freeman sets record
Memphis left-handed reliever Sam Freeman set a club record for consecutive scoreless innings pitched with 23 on Saturday against Nashville.
Freeman, 26, broke the former record of 22 2/3 scoreless innings, which was set by Josh Kinney from June 28 to Aug. 12.
Freeman is 5-2 with a 2.94 ERA in 33 games and 49 innings at Memphis. He has 19 walks and 47 strikeouts. Freeman was 0-2 with a 5.40 ERA in 24 games and 20 innings for the Cardinals last season.