The Heat overcame a lackluster offensive performance by LeBron James, who shot only 5-of-13 from the floor en route to 15 points.
Bosh went a perfect 9-of-9 from the floor, and Miami shot 54 percent as a team.
Rashard Lewis, who started in place of the sore Shane Battier, hurt his former ballclub with 18 points.
Jameer Nelson hit five three-pointers and led the Magic, who shot 41 percent as a squad, with 21.
The Heat led by double digits for most of the fourth quarter.
Let's break down the keys to this one.
Efficiency In Spite of LeBron
It's not often you'll see the Heat play well offensively in spite of a poor shooting night by James, but that's exactly what happened against Orlando.
Fortunately for Miami, James was in prime form in terms of feeding his teammates, as the superstar tallied eight assists. He knew he didn't have it himself offensively, so he spread the ball out to make sure his Heat brethren picked up the slack.
Credit Michael Beasley for coming in and giving Miami 13 points off the pine.
Improved Second Half Ball Movement
The Heat seemed to be going through the motions in the first half, and in the second quarter, they turned it over six times.
That all changed in the third period, as Miami began producing crisp, clean ball movement which led to easy buckets at the rim. Before you knew it, the Heat were up by double figures.
Poor Shooting by Orlando
Outside of Nelson, who went 5-of-8 from deep, the Magic were terrible from the perimeter on Saturday night.
Victor Oladipo went 2-for-6, Tobias Harris went 1-for-5 and Arron Afflalo misfired on all five of his long range attempts.
Overall, Orlando shot 8-of-26 from beyond the arc.
A lot of the misses were good looks as a result of good ball movement, too.
Had a few more of those shots gone down, this game certainly would have been closer.