ST. LOUIS -- Lance Lynn is making the most of a surprise opportunity.
The Cardinals snapped a two-game skid with their fourth win in six games. Chicago, which lost five of its first six, had won two in a row.
Lynn (2-0) gave up four hits and one run in 5 1/3 innings. He struck out five, walked two and lowered his ERA to 1.50 in a game delayed almost 2 hours by rain.
The 39th overall pick in the 2008 amateur draft, Lynn allowed one run over 6 2/3 innings in his first start this season, a 9-3 win at Milwaukee on Sunday. He began the year with a 1-1 career mark.
Lynn gained a spot in the rotation when Chris Carpenter was put on the disabled list with a right shoulder injury before the start of the season. The husky, 6-foot-5 Lynn, who was originally headed to the bullpen, is enjoying his time as a starter.
"I'm just going to try and do what I'm capable of and not try to do too much," he said. "Just make pitches and try not to give up runs."
Cardinals manager Mike Matheny has been very pleased with Lynn's first two efforts, especially Saturday's performance.
"I thought he was very good. He's just got good movement on his fastball," Matheny said. "Obviously, he's got some velocity on it. We all have high expectations."
Lynn, in his fourth major league start, set Chicago down in order in three of the first four innings. He gave up just two hits over the first five innings before tiring in the sixth.
"He's a big guy, a strike-thrower," Cubs manager Dale Sveum said. "You don't get many guys on against him. We really couldn't get anything going."
The Cardinals broke open a scoreless game with four runs in the fourth off Chris Volstad (0-1). Molina brought in Matt Holliday and Matt Carpenter with a single up the middle. Daniel Descalso had an RBI triple and Tyler Greene added an RBI single.
Carpenter, filling in for Lance Berkman at first base, had the key hit in the inning, smashing a 3-2 pitch off the top of the wall in right. The drive put runners on second and third with one out.
"Biggest pitch of the inning," Volstad said.
Berkman has a strained left calf and is day to day. Carpenter is hitting .278 with five RBIs.
"Obviously, we need Lance to get healthy, but until he does, hopefully I can get the job done," Carpenter said. "I just want to have good, positive at-bats and play good defense."
But the St. Louis bullpen allowed just two hits over the final three innings. Romero turned in 1 2/3 innings of scoreless relief. Fernando Salas and Marc Rzepczynski pitched the eighth. Jason Motte retired the side on seven pitches in the ninth.
"Everybody threw well and it was a win," Lynn said. "So you've got to be happy."
Volstad allowed six hits and three runs over six innings. He struck out four and did not walk a batter but was unable to overcome a 13-pitch hiccup in the fourth inning.
"Other than that, I felt like I did well," Volstad said. "I was using my changeup really well."
Chicago outfielder Marlon Byrd went 0 for 3 and is 2 for 27 this season.
Castro committed two errors at shortstop and has four on the season. His high throw on a grounder by Holliday started the four-run fourth.
The Cardinals were without World Series MVP David Freese. The third baseman was scratched before the game with soreness in a finger on his right hand.
"He could have gone," Matheny said. "He felt something weak in his hand. We're going to keep a close eye on it."
Freese, who is day to day, got hurt in an at-bat in Friday's home opener.
The start was delayed 1 hour, 59 minutes by rain. ... The Cardinals held a pregame ceremony to present World Series rings to players and coaches. Sveum made his players watch the festivities. "It's important to show respect for the world champions," Sveum said. "And it's a pretty awesome ring." ... In the series finale Sunday, both teams will mark the 65th anniversary of the day Jackie Robinson broke baseball's color barrier. All players will wear No. 42 as part of a tribute to Robinson's legacy.