Kendrick singled in a run in the second and doubled home two more in the sixth to highlight the Los Angeles offense. Torii Hunter and Mark Trumbo each drove in the run for the Angels, who snapped a three-game losing streak.
Williams (1-1), who began the season on the disabled list with a hamstring injury, gave up three runs on seven hits over 6 2/3 while striking out six. He is part of the Los Angeles rotation after having started no more than six games in any of the last four seasons.
Kendrick's two-run double gave Los Angeles a 6-1 lead, enough cushion to withstand a two-run homer by Baltimore's Nolan Reimold in the seventh.
Jordan Walden worked around a walk in the ninth to collect his first save.
The loss went to Brian Matusz (0-3), who surrendered four runs on eight hits in five frames.