Bell drove in three runs as the Astros increased their lead in the NL Central to 3 1/2 games over second-place Pittsburgh.
Mike Hampton (13-9) gave up eight hits in 7 2/3 innings and won for the 10th time in his last 12 decisions. Russ Springer got two outs for his third save.
Andres Galarraga went four for four for the Rockies, who lost for only the second time in 13 games. Dante Bichette added a two-run homer and sacrifice fly for the Rockies.
(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)
NEXT SERIES FOR DODGERS
WHO: Houston Astros
WHERE: at Houston
WHEN: Friday: 5 p.m.; Saturday: 5 p.m.; Sunday: 11:30 a.m.