Kemp hit his major league best eighth homer of the season and his MLB-best 20th RBI. He finished 3-for-3 with a walk.
The other Los Angeles run came on a third-inning single by Andre Ethier -- his 19th of the season -- and the Dodgers went on to improve their record to 11-3.
Ed Lilly (2-0) went six innings to get the victory, allowing a run on four hits. Javy Guerra recorded two of the 11 strikeouts by Los Angeles pitching and picked up his seventh save of the season with a perfect ninth.
J.A. Happ (1-1) took the loss, giving up three runs on eight hits in six innings. It was Houston's fifth loss in six games. Seven of Houston's nine losses this year have come by either one or two runs.