Harris tied his career high in points, finishing 14 of 17 from the field. Nikola Jokic added 14 points, nine rebounds and eight assists to help the Nuggets snap a two-game slide and improve to 13-4 at home this season.
Denver used a 37-18 third quarter to take control.
Devin Booker led Phoenix with 17 points and Greg Monroe filled in for starting center Tyson Chandler and had 16 points and 10 rebounds. Marquese Chrissadded 16 points, Josh Jackson 14 and TJ Warren 13.
The Suns had some issues getting to Denver after their 104-103 comeback victory over the Atlanta Hawks in Phoenix on Tuesday night. Waiting at Sky Harbor International Airport until 2 a.m., the Suns were finally sent home as mechanical problems delayed their flight until noon.
When they finally arrived at the Pepsi Center, a red-hot Harris welcomed them.
Harris hit his first eight shots and finished the opening quarter 9 of 10 from the field. He had 20 points in the first 10:34, including a nifty reverse layup that fooled two defenders. His driving layup late in the quarter put the Nuggets up 34-22.
The Suns responded, though, outscoring Denver 45-27 in the final 13:09 of the half. They shot 16 of 21 from the field in the second and led 67-61 at the break.
Denver took over after that, as the Suns hit only 5 of their first 28 shots in the third.
Suns: C Tyson Chandler (rest) sat out, while Monroe got the start for his first game action since Dec. 21. ... Jackson, the Suns' first-round draft pick, logged 24 minutes after not playing for the first time this season Tuesday.
Nuggets: Chandler blocked Warren at the basket in the final seconds of the first half and Jokic picked it up and heaved a full-court pass to Harris, who tapped in a layup at the buzzer. Harris finished the half 12 of 13 from the field. ... SG Will Barton played despite illness and 12 points. . PF Juancho Hernangomez (coach's decision) missed his fourth straight game. The 22-year-old Spaniard has logged only three minutes of playing time in the team's last nine games. ... Broncos general manager John Elway sat courtside. ... PF Kenneth Faried had four points and two rebounds in his first action since Dec. 15.
Suns: At San Antonio on Friday night.
Nuggets: Host Utah on Friday night.