Brown, who played briefly with the Bobcats before being traded to the Los Angeles Lakers along with Adam Morrison, helped break open an 87-all game early in the fourth quarter when he suddenly got hot.
Several of Brown's 3-pointers were contested with a hand in his face, but it hardly mattered.
Marci Gortat had 23 points and 10 rebounds for the Suns. Michael Beasley added 21 points and 15 rebounds.
Brown's sharp shooting offset a terrific night for Charlotte's Byron Mullens, who made six 3-pointers of his own and finished with 24 points and eight rebounds.
Kemba Walker added 17 points and eight assists for the Bobcats. Ramon Sessions had 17 points and nine assists.
The 6-foot-4, 210-pound Brown came into the game averaging 11.5 points per game, the Suns' leading scorer off the bench.
He entered the third quarter just 1 of 4 from the field, including 0 for 2 from 3-point range. But he hit six straight 3s to put the Suns ahead for good and scored 18 points in the fourth.
The Bobcats trailed 60-46 at the break after shooting just 33 percent in the first half.
Charlotte bounced back to tie the game at 85 early in the fourth quarter after Mullens and Tyrus Thomas began to heat up from the outside. Thomas finished with 10 points and gave the Bobcats a lift off the bench.
But they couldn't get over the hump and take the lead.
Charlotte coach Mike Dunlap came into the game worried about the Bobcats defending the paint and, sure enough, Gortat gave them fits inside in the early going as the Suns led by as many as 14 points. He dominated early on both ends of the court and hit 10 of 14 shots, almost all of those within a couple feet of the basket.
But Mullens' outside shooting and Walker's penetration off the dribble kept the damage to a minimum.
Charlotte played without Gerald Henderson, who will be out two to four weeks with a sprained left foot.
Jeffery Taylor, the team's second-round draft pick, started in Henderson's spot, giving the Bobcats two rookies on the floor for the opening tip. Taylor played 11 minutes and failed to score. Michael Kidd-Gilchrist, the No. 2 pick in the draft, had nine points and eight rebounds.