Among the reserves, Treveon Graham had a career-high 15 points and Jeremy Lamb had 15 for the Hornets, who have won three in a row.
Josh Jackson had a career-high 23 points and TJ Warren had 21 for the Suns, who have lost seven of eight and 10 of 12.
Dragan Bender and Devin Booker each had 18 points for the Suns, and Bender's fourth 3-pointer gave the Suns a 78-57 lead four minutes into the third quarter before the Hornets took over.
Booker suffered a left hip pointer in the fourth quarter and departed the contest.
Walker had 13 third-quarter points to help the Hornets get within eight at the end of the period, and center Cody Zeller made a three-point play for a 106-96 lead with seven minutes left to cap the Hornets' 20-2 run to open the fourth.
The Sun never were closer than five after that.
Graham's 3-pointer with 35 seconds remaining made it 115-107 and sealed the victory.
Howard had 14 rebounds and the Hornets had a 43-39 edge on the boards.
The Suns shot 53.2 percent and made 15-of-29 3-pointers, but they committed 19 turnovers to Charlotte's eight.
Bender started at power forward for Marquese Chriss, who was held out for what the Suns called a violation of team rules. ESPN reported Chriss had a verbal altercation with the team's strength coach after Friday's loss to Utah.
The Suns used a 15-3 run for a 56-45 lead in the second quarter. Jackson had eight points, including two 3-pointers, and Warren had seven in that stretch. The Suns made 8 of 14 3-pointers in the first half for a 59-48 lead.
The game featured the two most accurate shooters among the 40 players with at least 10,000 career rebounds.
Suns center Tyson Chandler entered with 10,045 rebounds and a 59.5 field goal percentage. Howard had 12,736 rebounds and a 59.3 shooting percentage. Howard is the league's leading active rebounder, ranking 18th in NBA history.
--Field Level Media
Charlotte | Phoenix | |
Nicolas Batum 22 | Scoring | Josh Jackson 23 |
Nicolas Batum 5 | Assists | Devin Booker 9 |
Dwight Howard 14 | Rebounds | Tyson Chandler 10 |
Dwight Howard 6 | Free Throws Made | Alex Len 4 |
Michael Carter-Williams 3 | Steals | TJ Warren 2 |
Dwight Howard 3 | Blocks | Tyson Chandler 1 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Charlotte | 115 | 41.7 | 10-38 | 25-29 | 24 | 43 | 6 | 12 | 8 |
Phoenix | 110 | 53.2 | 15-29 | 13-13 | 24 | 39 | 4 | 4 | 19 |