(Best E Casino) - The Chicago Cubs still own a seemingly-comfortable lead atop the NL Central standings, but have hit a wall as of late. The Cubs will try to avoid losing their fifth straight game and salvage the finale of a three-game series tonight versus the Houston Astros at Wrigley Field.

Chicago is 4 1/2 games ahead of the Milwaukee Brewers in the division standings and was handed a 9-7 loss in 11 innings on Tuesday. Relief pitcher Kerry Wood allowed a two-run homer to Geoff Blum in the top of the 11th inning to absorb the loss and starter Carlos Zambrano, who was scratched from his Sunday afternoon start against Philadelphia because of a sore arm, was taken out of the game after five innings.

Zambrano gave up three runs on five hits and three walks in the no-decision. He is expected to see team orthopedist Stephen Gryzlo on Wednesday. Geovany Soto finished with three hits, including a homer, and Alfonso Soriano, Mark DeRosa and Jim Edmonds each went deep in defeat. The Cubs maintained their lead over the Brewers after Milwaukee lost to the New York Mets last night.

Ryan Dempster has a good shot at ending the Cubs' losing streak as he is set to take the mound on Wednesday. Dempster is 3-0 over his last four starts, but did not factor into a 6-4 victory versus Philadelphia the last time out on August 28. He was reached for four runs and eight hits in six innings to keep his record at 15-5 while slightly raising his ERA to 2.95 through 28 starts.

Dempster is nearly unbeatable at home, sporting a 12-2 mark in 17 trips to the Wrigley Field mound. In 40 career games (14 starts) against Houston, the righty is 4-9 with a 4.54 earned run average. Dempster is 1-2 in three starts versus the Astros this season.

Houston has won seven in a row and will shoot for a series sweep tonight. In Tuesday's extra-inning affair, Wesley Wright recorded the win after tossing two scoreless innings of relief. Hunter Pence had four hits and fell a homer short of the cycle, while David Newhan and Miguel Tejada each had two hits and two runs batted in for Houston, which is 7 1/2 games behind Milwaukee in the wild card standings.

Starter Brandon Backe allowed three runs in 4 1/3 innings in the no-decision.

Taking the ball for the Astros on Wednesday will be Randy Wolf, who is 2-1 with a 4.70 earned run average in seven starts since joining the club in July. Wolf previously pitched on August 29 versus St. Louis and did not post a decision after giving up two runs -- one earned -- in six innings of a 3-2 win against the Cardinals.

The left-hander, who is 8-11 overall with San Diego and Houston this season, is just 1-7 on the road in 2008. Wolf is also only 2-6 with a 4.98 ERA in 13 career meetings with the Cubs. He lost his only matchup against them this season on May 12, when he surrendered seven runs in just four innings.

Houston leads the 2008 season series with Chicago by an 8-6 count.