ST. LOUIS -- One big inning and Jeff Samardzija's pitching were all the Chicago Cubs needed Tuesday night.
Chicago scored all of its runs in the top of the first, and Samardzija outpitched 10-game winner Adam Wainwright as the Cubs recorded a 4-2 decision over the St. Louis Cardinals at Busch Stadium.
Samardzija (4-7) gave up Carlos Beltran's line drive homer off the right field foul pole in the bottom of the sixth inning and nothing else which mattered until a ninth-inning rally. He worked 8 1/3 innings, scattering seven hits and walking one while fanning six.
Kevin Gregg relieved after one-out singles by Matt Holliday and Allen Craig in the ninth and earned his 10th save despite allowing an RBI single to Yadier Molina. Gregg induced a game-ending double play from David Freese as pinch runner Shane Robinson was called for interfering with shortstop Starlin Castro on his pivot. Second base umpire Fieldin Culbreth made the ruling.
After making two quick outs in the top of the first, the Cubs (29-40) jumped all over Wainwright for four runs.
Nate Schierholtz and Alfonso Soriano clubbed consecutive doubles for the first run. Ryan Sweeney lined a 1-1 pitch into the right field seats for his second homer of the year, and Cody Ransom followed with a towering solo shot over the wall in left that gave Samardzija a rare cushion.
The right-hander picked up 15 outs via grounders.
Samardzija allowed the leadoff man to reach in the second, fourth and fifth, but used double play balls to quell any thoughts of a rally.
Wainwright (10-4) permitted just three hits after the first inning, making his way through seven innings before calling it a night. He walked none and struck out three.
Despite the defeat, the Cardinals (45-26) maintained their 2 1/2-game lead in the National League Central when the Pittsburgh Pirates blanked the Cincinnati Reds 4-0.
NOTES: Chicago manager Dale Sveum gave 1B Anthony Rizzo the night off, his first of the year. Rizzo has 10 homers, but none since May 18, and is hitless in his last 10 at-bats to drop his batting average down to .241 ... St. Louis manager Mike Matheny said that rookie LHP Tyler Lyons probably would take his regular turn in the rotation Friday against the Texas Rangers despite losing his last three starts, including a 7-2 decision Sunday in Miami. There was speculation that RHP Joe Kelly could get the call in Lyons' place ... Cardinals RHP Fernando Salas was scheduled to start a rehabilitation assignment Tuesday night with Triple-A Memphis. Salas has been out nearly a month due to right shoulder inflammation.