HOUSTON - Ramon Martinez's two-run double capped a three-run ninth inning, lifting the Cubs past the Astros 4-2 on Tuesday night.
Aramis Ramirez hit a tying single in the ninth off closer Octavio Dotel, who blew his third save in 15 chances.
Tom Goodwin led off the inning with a single, Ramirez followed with a hit and Derrek Lee was intentionally walked to load the bases.
Martinez then sent a 3-and-2 pitch to leftfield, scoring Goodwin and Ramirez for the go-ahead runs. Cubs closer LaTroy Hawkins got three outs for his sixth save of the season.
Kyle Farnsworth got the win, allowing one hit in the eighth.
The Astros nearly pulled off the win by scoring two in the sixth off struggling starter Carlos Zambrano.
Zambrano led off the inning by walking Lance Berkman and giving up a double to Jeff Kent. Morgan Ensberg followed with a single that scored both, putting the Astros up 2-0.
Zambrano found himself in another jam later that inning, giving up a single to Orlando Palmeiro and a double to Jason Lane. An intentional walk to Brad Ausmus loaded the bases with one out.
But Zambrano forced Wade Miller to pop up to second baseman Todd Walker, and Ramirez made a fine stop on Craig Biggio's hit to third base and threw him out to end the inning.
The Cubs replaced Zambrano with Kent Mercker to start the seventh.
Miller, who pitched six shutout innings in his start last week against Seattle, was almost as good this time, but it wasn't enough.
He gave up a third-inning homer to Ramon Martinez and four hits in 61/3 innings, allowing the Astros' sputtering offense to stay in the game despite Zambrano's strong effort.
The Astros looked headed for their second shutout loss in the past eight games before Zambrano started to struggle in the sixth.
The Astros, forced to juggle their starting lineup because of recent injuries to Jeff Bagwell, Adam Everett and Richard Hidalgo, finished with nine hits but left 12 men on base.
Miller gave up a homer to Martinez in the third on a 3-and-2 pitch. The ball landed deep in the leftfield seats and bounced into the concourse, giving the Cubs a 1-0 lead.
Houston has failed to score more than five in 14 consecutive games.
