Durant's run of 41 consecutive games this season with at least 25 points was the third-longest streak in NBA history.
"It was a two-man race, and then toward the end, it was kind of a no-brainer," Griffin said.
James averaged 27.1 points, 6.9 rebounds and 6.3 assists while shooting nearly 57 percent from the field.
Griffin averaged 24.1 points and 10.1 rebounds.
"It's an honor, really," he said of finishing third. "It's hard to believe. I'm honored and humbled by that."
Durant scored at least 40 points 14 times. He also averaged 7.4 rebounds and a career-high 5.5 assists while shooting 50 percent from the field.
While Westbrook was out after his most recent knee surgery, Durant averaged 35 points and 6.3 assists as the Thunder went 20-7 and remained among the league's elite.
Westbrook's injury gave Durant an opportunity to use his improving skills as a playmaker.
"I've always been a player that was excited for my teammates' success," Durant said.
Teammates and opponents say Durant became a more complete player this season. They praised him for improving his court vision, consistently making the extra pass and moving more efficiently without the ball.
"I think we take it for granted," teammate Nick Collison said. "To be able to stay on for long periods of time -- have to cut hard, catch the ball in the right spot and defend on the other end -- is tough to do. To be able to show that shows that he has an edge to him. He doesn't take a night off."
Durant's slight build could be considered one of his few weaknesses, but he has improved in dealing with opponents who try to push him around.
"I don't really think that matters with him," Westbrook said. "He just takes on the challenge. When people try to be physical, he takes on the challenge and becomes more aggressive."
Though Durant's consistency stood out this season, he had several exceptional games. He scored 48 points on Jan. 4 at Minnesota, then scored 48 again two games later at Utah. He scored a career-high 54 points in a home win against Golden State on Jan. 17 and two games later scored 46 at home in a victory against Portland.
Two games after that, he had a triple-double -- 32 points, 14 rebounds and 10 assists -- in a win at Philadelphia, and he followed that with 41 points in a victory over Atlanta. He scored 51 points at Toronto on March 21 in a staggering 53 minutes and hit the game-winning 3-pointer with 1.7 seconds left in double overtime.
He capped it off in the season finale by scoring 21 of his 42 points in the fourth quarter against Detroit and winning the game with a dunk with 16.5 seconds left. The Thunder overcame a 10-point deficit in the quarter to clinch the No. 2 seed in the Western Conference playoffs.
"I put in so much work and so many people helped me," he said. "I feel like we all won it. Our equipment guy gave me a hug today and said, 'This is my first MVP,' and I thought about that. And I said, 'Yeah, this is our first MVP.' I couldn't have done it without the teammates, without the trainer. Everybody. We all just did this together."
Information from ESPN.com's Marc Stein, ESPN.com's Tom Haberstroh, ESPN Stats & Information and The Associated Press was used in this report.