The reigning MVP finished the game with 43 points, including 25 in the first quarter, while Chris Bosh made a string of shots late on to hold off the Cleveland fightback.
Neither side were able to open up a substantial lead during regulation, but Wesley Matthews stepped up for the Blazers in overtime, adding a three-pointer to put them ahead, before setting up Damian Lillard to extend the lead.
DeMarcus Cousins scored 12 of his 24 points in the final 12 minutes of regular time to lead the Kings back into the game, before adding six in overtime, while Isaiah Thomas and Rudy Gay also finished with 24.
The home side were already 10 points ahead at the break, but outscored their opponents 30-19 in the third quarter, led by Stephen Curry, leaving the Magic on a six-game losing streak.
Results in full: Miami Heat 100-96 Cleveland Cavaliers, Toronto Raptors 113-118 Atlanta Hawks, Milwaukee Bucks 115-120 Portland Trail Blazers, Washington Wizards 111-117 Sacramento Kings, Orlando Magic 89-103 Golden State Warriors