The Thunder outscored the Hawks 70-36 in the paint.
Gilgeous-Alexander was 15 of 24 from the field and had six assists, six rebounds and a pair of steals.
Oklahoma City has won two straight after losing back-to-back games to San Antonio, marking its first losing streak of the season.
The Thunder have won 24 consecutive regular-season games against Eastern Conference opponents, including all six matchups this season.
The Thunder haven’t lost at home to an Eastern Conference opponent since March 2024.
The Hawks have dropped seven consecutive games.
The Hawks were without not only Kristaps Porzingis (illness), but also Trae Young (right quad contusion) and Jalen Johnson (illness).
The Thunder were without Isaiah Hartenstein, who suffered a calf injury in Oklahoma City’s win over the 76ers on Sunday.
After trailing by four at halftime, the Thunder appeared to seize control in the third with a 30-11 run to go up 100-85. Gilgeous-Alexander scored nine of his 15 third-quarter points during the stretch.
But the short-handed Hawks weren’t going away, and responded with an 18-6 run, hitting 7 of 9 shots to cut Oklahoma City’s lead to 106-103.
Atlanta was within four after Nickeil Alexander-Walker’s 3-pointer with less than four minutes remaining.
However, the Thunder finally put the game away with an 8-1 run, punctuated by Alex Caruso’s steal and feed to Chet Holmgren for a dunk.
Holmgren finished with 24 points, nine rebounds and three blocks while Jalen Williams scored 20.
Oklahoma City shot 54.1% from the field, topping the 50% mark for the third time in four games.
Alexander-Walker, playing against his cousin Gilgeous-Alexander, led the Hawks with 30 points, hitting six 3-pointers. Alexander-Walker scored 12 points in the fourth to help Atlanta stay in the game until late.
The Hawks made a season-high 25 3-pointers, with Vit Krejci and Zaccharie Risacher hitting four each.
Onyeka Okongwu added 26 points, 14 rebounds and six assists in the loss.
