Cleveland played without superstar LeBron James, who suffered a sprained ankle 24 hours earlier against Portland -- when he still managed to hit the winning layup and score 37 points.
After suffering through a team-record 14-game losing streak, Seattle won its second straight. The Sonics halted the skid Tuesday with a surprising victory over San Antonio.
Seattle had a 16-point lead entering the fourth quarter, but Cleveland closed within four with 37 seconds to play on a layup by Larry Hughes. The Cavaliers regained possession, but an offensive foul called on Daniel Gibson with 13 seconds left ended their hopes.
Seattle's Luke Ridnour then made two free throws for the final margin.