Durant scored 17 of his 36 in a nightmarish final quarter for James and his team, leading the Thunder to a 105-94 victory in Game 1 on Tuesday night.
Teaming with Russell Westbrook to outscore the Heat in the second half by themselves, Durant struck first in his head-to-head matchup with James, who had seven points in the final quarter and couldn't stop the league's three-time scoring champion.
Westbrook turned around a poor shooting start to finish with 27 points, 11 assists and eight rebounds. His three-point play on Oklahoma City's final possession of the third quarter gave the Thunder its first lead, and the Heat never caught up.
Scoring in nearly every way possible, Durant finished 12 of 20 from the field and added eight rebounds. He and Westbrook outscored the Heat 41-40 in the second half.
James finished with 30 points, his most in any of his 11 Finals games, but had only one basket over the first 8:15 of the fourth