Smith finished two assists shy of a triple-double. Ivan Johnson added 12 points and 15 rebounds.
Ramon Sessions led the Bobcats with a season-high 27 points. Kemba Walker, who had a career-high 35 points on Monday, was limited to 11 on 4-of-11 shooting.
The win gave the Hawks a four-game sweep of the season series and extended their overall winning streak to seven against the Bobcats.