LeBron James realised his dream of winning multiple NBA crowns with the Miami Heat with the Finals MVP delivering a magnificent 37-point performance to sink the San Antonio Spurs and defend the title.

James's points tally was the highest in a Finals Game Seven in 44 years since Jerry West's 42 for the Los Angeles Lakers against the Boston Celtics in 1969 and his display was worthy of a player now widely viewed as one of the greatest to have played the game.

"It feels great. This team is amazing and the vision that I had when I decided to come here is all coming true," said James, who joined the Heat in 2010 after five seasons with the Cleveland Cavaliers.

"Through adversity, everything we have been through, we have been able to persevere and to win back-to-back championships. It's an unbelievable feeling."

James crowned his performance with a key jump shot down the stretch that put Miami in command at 92-88 with 27.9 seconds left.

The four-times league MVP then grabbed a steal off a Manu Ginobili attempted pass to Tim Duncan to ensure the win. Duncan fouled him and James then sank both his free throws.

Miami had trailed 3-2 in the series before coming back to South Florida for the final two games and James found his scoring form at the perfect moment, making 32 points in the dramatic Game Six overtime win.

James, strangely unpopular with many NBA fans, was heavily criticised in the media for his performance in Miami's 2011 Finals loss to Dallas but came back to win against Oklahoma last year and termed this season's triumph as a greater achievement.

"This was the toughest championship. Everything we have been though this post-season, we weredown every odd game, we were scratching for our lives in Game Six down five with 28 seconds to go," he said.