How it happened: Veteran right-hander Rodrigo Lopez gave the Cubs 5 1/3 decent innings in his ninth start of the season. Two-run doubles by Carlos Pena in the first and Geovany Soto in the sixth provided a cushion for the Cubs starter. The Astros knocked out Lopez with two runs in the bottom half of the sixth on a Matt Downs double. On the downside, the Cubs committed two more errors after making four on Sunday. The team leads the majors with 103 miscues. Although Starlin Castro's error in the sixth led to an unearned run, he also had three highlight-reel plays at shortstop. Castro has committed just two errors since the All-Star break.
What it means: The Cubs are now 12-3 since July 31, the third best record in baseball over that time frame. The North siders already have more wins in August than they did in the entire month of July (9).
Outside the box: Left-hander Scott Maine was recalled from Triple-A Iowa to replace Carlos Zambrano on the 25-man roster. Right-hander Casey Coleman also joined the team on Monday and will be activated before his start on Wednesday in place of Zambrano.