Ilgauskas finished with 25 points and LeBron James had 34 points, 16 rebounds and 10 assists for his 26th career triple-double for the Cavaliers, who have won two straight games and seven of their last eight.
Mo Williams, who left the game with a knee injury in the first quarter, came back in the second and finished 27 points for Cleveland.
Tyreke Evans scored 28 for the Kings, who got 18 points apiece from Omri Casspi and Jason Thompson, and 17 points and 12 rebounds from Spencer Hawes.
Sacramento shot 0-for-7 from the field in overtime.
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