Hemsky beat Kings goalie Jason LaBarbera with a backhand to put the game away for Edmonton, which won for the third time in four games.
LaBarbera came into the game in the second period in relief of starter Erik Ersberg, who was removed after allowing three goals on 13 first-period shots. LaBarbera finished with 30 saves.
The Kings scored four times in the second period and carried a 4-3 lead into the third. Dustin Penner made it 4-4 in the third when he picked up a pass from Shawn Horcoff in front of the goal and scored with 11:37 left in regulation.