CHICAGO -- Pete Kozma picked a big spot for his first major league home run.

Kozma had two hits and drove in two runs to help Kyle Lohse and the short-handed St. Louis Cardinals win for the sixth time in seven games, holding their lead in the NL wild-card race with a 6-3 win Sunday over the Chicago Cubs.

Minus All-Stars Yadier Molina and Carlos Beltran from the starting lineup, the Cardinals stayed 2 ½ games ahead of Milwaukee for the second wild-card spot.

Kozma homered in the sixth inning to give his team a 4-2 lead, and added an insurance run with a sacrifice fly in St. Louis' two-run eighth.

"Every game means something," Kozma said. "I feel pretty good getting in there every day and working out the jitters."

A quick-thinking Cardinals fan, Jeff Barabasz, caught the ball and immediately sat on it. He gave a decoy ball to his 13-year-old son, Matthew, who threw it back onto the field to appease the Wrigley Field faithful.

They met Kozma after the game to return the real home run ball, posing for pictures with the 24-year-old.

"That was pretty cool," Kozma said. "It's also big to help your team out in a big spot."

Kozma was called up when shortstop Rafael Furcal went down with a strained right elbow at the end of August and has impressed manager Mike Matheny, earning regular playing time.

"I've been impressed with the way he moves around shortstop, and he's taken good at-bats for us," Cardinals manager Mike Matheny said. "He's had tough at-bats. That eight-hole is not an easy place to be. He's done a nice job with the opportunities he's had."

Closer Jason Motte also kept a souvenir from the game after recording his 40th save.

Motte joins Bruce Sutter, Lee Smith and Jason Isringhausen as the only closers in Cardinals history to post a 40-save season.

Motte has six saves in the team's last seven games.

"If I'm out there converting saves, that means we're winning," Motte said. "That's what it's about, it's about winning."

Lohse (16-3) made his team-leading 32nd start, giving up three runs and five hits in six innings.

Molina did not play for the defending World Series champions because of lower back spasms, having hurt himself while getting out of the way of a pitch Saturday. The catcher was feeling better, manager Mike Matheny said, still had some discomfort.

Beltran did not start because of what Matheny believed to be food poisoning. The outfielder had a pinch-hit RBI single during a two-run eighth.

He didn't join the team in the dugout until the fifth inning, and went to the plate without any warm-up swings.

Allen Craig got three hits and drove in two runs for St. Louis.

"The more I watch him, the more I'm impressed," Matheny said of Craig. "Everything about him."

Cubs starter Justin Germano (2-9) worked 5 2/3 innings, giving up four earned runs and 10 hits.

Craig hit a two-run double with two outs in the third and David Freese had an RBI single. St. Louis would have had the bases loaded for Craig, but a baserunning mistake found both Matt Carpenter and Matt Holliday on third base and Carpenter was tagged out.

Alfonso Soriano hit his 31st homer for the Cubs, giving him a career-high 105 RBI.

"He just keeps going, he's had to play a lot of games this year with very few days off," Cubs manager Dale Sveum said. "He's done one heck of a job -- left field, at the plate and everything about this season has been one of his best."

Chicago got two runs back in the fourth on Welington Castillo's RBI double and a wild pitch.

Notes

• The Cubs saluted retired pitcher Kerry Wood in pregame ceremonies. Wood, a 12-year Cubs veteran and 1998 NL Rookie of the Year, retired in May with the third-most strikeouts in team history (1,470). "I was fortunate to call Wrigley Field my home," he said. "A lot of great memories and a lot of great moments.". The Cardinals head to Houston, where Lance Lynn (16-7, 3.79) will take the mound opposite Fernando Abad (0-5, 5.11) on Monday.
• Chris Rusin (1-2, 6.00) pitches the series opener for the Cubs in Colorado on Monday against the Rockies' Jorge De La Rosa (0-1, 12.27).
• Outfielder Matt Holliday left in the ninth inning when his back tightened up. Holliday said it's something he's dealt with a couple times this season, noting it's not as bad as previous instances.