Adding further concern for Cleveland, however, was the sight of their inspirational All-Star point guard Kyrie Irving limping off the court during overtime after an awkward fall.
Irving had been in dazzling form for his team at both ends of the court with 23 points, seven rebounds and four steals.
With James sparking the offense and Tristan Thompson spearheading a stifling defense, the Cavaliers initially outshot the Warriors from the floor and they streaked 14 points in front before ending the first quarter with a 29-19 lead.