Miami held a tenuous 69-68 lead before Wade caught fire and helped push the home side's advantage to double digits with about four minutes remaining.
Wade erupted for 12 consecutive Heat points in the fourth, where he scored 14 of his game-high 31, his late heroics turning a tight contest into lock-up for Miami.
"We needed a jolt of energy. I decided I would be the one who brought it," Wade told reporters. "It's tough to have that energy every day.
"It's a long season, we're only human. We're trying to find ways to win ball games."
Chris Bosh added 23 for the Heat (33-11) to help offset a rare off shooting night from LeBron James, who only had 14 but chipped in with 12 rebounds and seven assists.
Dwight Howard recorded 18 points and 11 rebounds for the visiting Magic (29-17) but they were stifled in what was a defensive Florida grudge match.
Orlando fell five games behind Miami in the Southeast Division and lost the latest match-up in the rivalry.
The Magic defeated Miami in their previous meeting on Tuesday, but the Heat raised their defensive intensity this time and forced the visitors to shoot just 39 percent.
Bosh dominated the opening quarter with 12 points and Miami built a 12-point lead, only to have it trimmed to three by halftime.
"Chris Bosh, a great player, with Ryan Anderson guarding him looked like a totally different player in the second half than he did in the first half," said Magic coach Stan Van Gundy.
"Why we came into such a game and didn't bring any effort early is hard to understand."