Held to 12, 12 and 11 points in his previous three games, Carter surpassed those totals with 14 in the first quarter, then capped the evening with two free throws and a steal in the final 10 seconds to stop Cleveland's last rally.
Jason Kidd could sense Carter was primed for a big night practically before he broke a sweat.
"I said, 'He's going to go for 50," Kidd said. "He came out aggressive and you could just see he was in tune tonight."
The showdown between two of the NBA's premier scorers was reminiscent of the last time the teams played here, last April. Though Cleveland won that game 108-102 to snap New Jersey's 14-game winning streak, Carter scored 33 points to James' 37.
This time, Carter had help from the Nets' bench players, who shot a combined 10-for-20 and started a surge late in the third quarter that gave New Jersey an 89-73 lead with 10 minutes left in the game.
Bostjan Nachbar kicked it off with a drive and dunk down the middle of the lane followed by a 3-pointer, and Carter capped it with a 3-pointer.
"I guess the shooting gods were on my side tonight," said Carter, who had made 12 of his last 48 shots before a 10-for-18 performance. "I knew I just had to keep playing, keep shooting and eventually it would go in."
The Nets improved to 10-3 when scoring 100 points. They have won just once this season when they failed to reach 100.
They nearly didn't win this one. James and teammate Damon Jones, who scored 14 points off the bench, nearly brought Cleveland back in the fourth quarter. But they couldn't dig out of the hole they made for themselves by shooting a combined 11-for-45 in the second and third quarters after making 11 of 18 shots in the first 12 minutes.
The loss dropped Cleveland's road record to 3-8. The Cavaliers are 11-2 at home.
"We're getting very close to figuring it out," James said. "Our last two road games have been pretty good, a lot better than in the past. We're starting to find easier ways to score baskets. If we play the defense we've played all season, we'll find a way to win."
In contrast to Cleveland, New Jersey has struggled at home. Wednesday's win evened the Nets' home record at 8-8, a considerable downturn for a team that was 29-12 at Continental Airlines Arena a season ago.
"We want to start to become a better team, and to become a better team you have to play better each time out," coach Lawrence Frank said. "We played better tonight than we did against Golden State, and now we have to play better on Friday against the Lakers."
Kidd scored nine points to reach 13,000 for his career. NBA executive vice president of operations Stu Jackson presented him with a commemorative ball in honor of his moving past Wilt Chamberlain last Monday for third place on the triple-double list. ... Jason Collins scored a season-high nine points for New Jersey. ... The Nets' planned move to Brooklyn for the 2009-10 season cleared a major hurdle Wednesday when the state Public Authorities Control Board voted unanimously to authorize the Atlantic Yards project. "The organization has been committed to making this a metropolitan team, a regional team," Frank said. "Obviously, we love the support in New Jersey, but the intent was to move to Brooklyn and this was a major step in that direction." ... The Nets wore their red uniforms, which are normally their alternate road colors.