It was the first win in Houston during this century for the Bucks.
Milwaukee built a 17-point advantage early in the final period but Houston cut the deficit to four and had a chance to get closer than that in the last minute.
A steal by Milwaukee's Drew Gordon with 46 seconds left, however, led by two free throws by Drew Gooden that ended Houston's comeback bid.
Jennings and Jackson both scored 20 points and Mike Dunleavy Jr. had 18. The Bucks have won three of their last four.
Kevin Martin scored 29 points for the Rockets, who had won seven in a row. Milwaukee had not won in Houston since Nov. 2, 1999.