Chicago Cubs left fielder Alfonso Soriano's three-run home run off St. Louis Cardinals reliever Kyle McClellan in the top of the eighth inning snapped a 1-1 tie and delivered a big blow to the Cardinals' Wild Card hopes.

The Cardinals opened the scoring in the bottom of the second inning when left fielder Skip Schumaker scored on a sacrifice by starting pitcher Chris Carpenter. That lead remained in place until Cubs first baseman Carlos Pena doubled home Darwin Barney in the top of the sixth.

Carpenter, who had was 2-0 with a 1.50 E.R.A. over his last three starts, a span in which the 36-year-old agreed to a two-year, $21 million contract extension, surrendered five hits, walked two and struck out five over seven innings before turning the game over to the bullpen.

Barney led off the top of the eighth with a triple to right center. McClellan got Bryan LaHair to ground out to first base, which led to an intentional walk of Pena and Soriano taking a 2-0 pitch from McClellan out of the park. The Cubs added an insurance run on an RBI single by Starlin Castro in the top of the ninth, while Cubs closer nailed the door shut with a 1-2-3 bottom of the ninth to preserve the win.

With the loss, the Cardinals fell three games behind the Atlanta Braves in the National League Wild Card race. The Braves jumped on Washington Nationals starter Stephen Strasburg, scoring three runs in the top of the first in their 7-4 win on Friday night.