Lynn opened the team's final road series of the regular season knowing that additional separation was up for grabs in the chase for the second National League Wild Card. Milwaukee had lost earlier in the day. The Dodgers were idle. By claiming a series-opening victory, the Cardinals now sit 3 1/2 games in front of both. Everyone else is at least 5 1/2 back.
It's a lead the Cardinals have to hold through only eight more games, two more of which come against this 104-loss Houston team preparing for an NL Central farewell.
"You have to beat the teams you're supposed to beat," Lynn said. "That's what we want to do -- get on a streak where we're playing well and maybe do some things."
It took 28 pitches for Lynn to wrap up the first, an inning that has haunted him all year. He was rewarded once he did. Matt Carpenter, who subbed in when David Freese rolled his ankle just before first pitch, drew a two-out walk from Astros starter Fernando Abad the following half inning.
Abad's day ended there due to an oblique injury, and reliever Fernando Rodriguez was greeted by Daniel Descalso's RBI triple.
Pete Kozma crushed a two-run homer to put the Cardinals up three. It was his second homer in as many games for the team's new everyday shortstop and eight-hole hitter.
"I feel like I can put the ball in play with some force, with some aggressive swings," Kozma said. "I kind of like hitting toward the bottom of the lineup because I can see what the pitcher likes to do."
Rodriguez said he should have thrown a few more warmup pitches after being summoned on the spot.
"That ball to Kozma ran back right over the middle," Rodriguez said. "There's a way to attack him, and I ended up missing my spot by a lot and got hurt."
Yadier Molina, returning from a back injury, delivered a solo homer in the fourth. Matt Holliday's two-run single in the seventh gave him 100 RBIs and provided even more breathing room for the Cardinals, who benefited substantially from winning a game by a comfortable margin. It meant that several recently overworked relievers could take a much-needed night off.
While Holliday's single provided that cushion, it was the bottom half of the lineup that carried the offense as a whole. The team's Nos. 6-8 hitters combined to go 6-for-10 and reached base eight times. The rest of the lineup produced only three hits.
"We've got to have those guys keep carrying us," Matheny said, "while we're having trouble getting everybody else going."
Lynn (17-7) righted his mechanics after a suspect first two innings and then thrived. He covered seven innings for the first time since July 16 and limited the Astros to one run, which wouldn't have scored if not for a wild pitch on a strikeout for Jason Castro.
"Early on I was having trouble hitting where I wanted to hit and they were putting some long at-bats on me," Lynn said. "That ran my pitch count up early. I had a quick third [inning], which helped, and then I was able to get right back to where I wanted to be."
Lynn scattered five hits and struck out nine.
He was saved another potential baserunner by Jon Jay's circus catch. After initially breaking the wrong way on Castro's fourth-inning liner, Jay caught himself, retreated and juggled the ball off his glove and his hand before making the catch.
"I'm just happy it ended up in my hand," Jay said. "I'm happy the recovery was good."
Lynn has won all three starts he's made since making the move back to the rotation and has come to resemble his early-season self. His ability to get out of the early innings unscathed was something Lynn had a particularly hard time doing in the first month after the All-Star break. That led to a short demotion to the bullpen.
In his last three starts, Lynn has allowed only two runs on 13 hits in 19 1/3 innings. His late-season renaissance has been huge in helping stabilize a Cardinals rotation that will be without Jake Westbrook indefinitely.
"I see him with a whole different demeanor," Matheny said. "His stuff looks a little better and I think the rest did him a lot of good, especially mentally."
The Cardinals have won nine straight against the Astros, outscoring them, 62-18.