The Texans took a 14-13 lead midway through the third quarter on Matt Schaub's 32-yard pass to Jacoby Jones, but Baltimore dominated the rest of the way with Cundiff kicking his third, fourth and fifth field goals of the game and Ricky Williams contributing a 4-yard scoring run with 4:01 to play.
Baltimore stayed a half-game in front in the AFC North with a 4-1 record and a three-game winning streak. Houston has dropped two straight and fell to 3-3.
Quarterback Joe Flacco completed 20-of-33 passes and scored Baltimore's first touchdown on a 1-yard run with 1:08 to go in the first period. Flacco's score finished off a 97-yard march that took 8:47 off the clock.
Schaub was good on 21-of-37 throws for 220 yards. Baltimore held Arian Foster, who led the league in rushing last year, to 49 yards on 15 carries.