Astros starter Chris Sampson pitched five scoreless innings and Luke Scott had a two-run double in a three-run first. Carlos Lee added an r-b-i single.
Cubs shortstop Cesar Izturis committed three errors as Chicago dropped to 3-and-5.
Jason Marquis took the loss in his first home start for the Cubs. He's 1-and-4 at Wrigley Field.
