Chris Bosh chipped in with 18 points and Dwyane Wade went for 17 points and seven assists for Miami, which has won three straight since a season-opening loss at Boston. Miami shot 53.7 percent from the field, but made only 5-of-16 from three-point territory.
Brook Lopez had a team-leading 20 points for the Nets, who opened the 2010-11 campaign with victories over Detroit and Sacramento. Devin Harris donated 13 points, while rookie Derrick Favors finished with 13 points and a game-high 13 boards in defeat.
Miami jumped out to a 29-18 lead after the opening 12 minutes behind 10 points from Wade and eight from Bosh.
Zydrunas Ilgauskas then scored the first six points of the second quarter as part of a 12-5 Heat run and after a James' driving layup and a dunk, Miami was ahead 41-23 with 7:13 before the half.
The visitors held a double-digit lead throughout the period and James Jones' three-pointer with 10 seconds remaining, put Miami up 58-42 heading into the intermission.
New Jersey was unable to cut into the deficit, as James' layup at the midway point of the third had Miami in front by a 68-53 margin and it would take a commanding 85-61 advantage into the final quarter.
The Nets never threatened the outcome in the fourth as Miami cruised to the easy victory.