Smith had 16 points and 13 rebounds on his 27th birthday. Al Horford led the Hawks with 25 points and 12 rebounds.
Ty Lawson paced Denver with a season-high 32 points. Corey Brewer had 19.
Two free throws by Danilo Gallinari with 2:34 remaining gave Denver its first lead of the final period at 98-97. Lawson's 3-pointer gave the Nuggets a 101-99 advantage before Horford hit a tying jumper.
Following a missed jumper by Denver's Kenneth Faried, Lou Williams made two free throws. Smith then stole the ball from Lawson and completed a fast break with a dunk over Brewer, who was called for a foul. Smith added the free throw for a 106-101 lead.
The Nuggets were without center Kosta Koufos, who remained at the team hotel with the flu. Timofey Mozgov had six points and 13 rebounds in his first start of the season.
Gallinari had 16 points and JaVele McGee added 11 for Denver.
Williams scored 16 points and Devin Harris had 12 for Atlanta.
The Hawks had first-half success with their big lineup, with Zaza Pachulia at center and Horford shifting from center to power forward. The big lineup usually benefits Horford, who has room for more scoring opportunities away from the basket.
Pachulia also thrived with extended playing time, scoring all 11 of his points in the second quarter as the Hawks took a 55-51 halftime lead.
The Hawks' biggest lead was 73-62 at the end of a 10-0 run in the third period.
NOTES: The Hawks ended a four-game losing streak in the series with their first win over the Nuggets since Nov. 7, 2009. ... Hawks G Kyle Korver was away from the team and with his wife, who is expecting the couple's first child. The team recalled rookie G John Jenkins from its Bakersfield NBA Development League affiliate. Jenkins did not play.
(Copyright 2012 by The Associated Press. All Rights Reserved.)