Russell Westbrook had 27 points — 21 in the first half — and 11 assists. Durant, who had 18 points in the fourth period, had 13 rebounds.
No other Oklahoma City player scored in double figures.
Oklahoma City (21-4) improved the NBA's best record and atoned for a 104-95 home loss to the Hawks on Nov. 4. That loss left Oklahoma City 1-2; it is 20-2 since then and hasn't lost since Nov. 23 at Boston.
The 12 straight wins matches the longest streak for the franchise since 1996, when it had a 14-game winning streak as the Seattle SuperSonics.
Jeff Teague led Atlanta with 19 points. Josh Smith had 17 points and 12 rebounds. Al Horford and Lou Williams each had 13 points.
The Hawks took their last lead at 19-17 on a follow shot by Anthony Morrow. The Thunder then went ahead with a 10-1 run that overlapped the end of the first period and the start of the second. Martin opened and closed the run with jumpers.
Oklahoma City stretched the lead to 17 on four straight free throws by Durant following fouls by Morrow late in the half.
The Thunder led 68-52 midway through the third quarter, but a technical foul against Smith with 3:12 remaining in the period seemed to spark the Hawks.
Smith sank a 3-pointer as part of Atlanta's 8-0 run to close the period. Anthony Tolliver scored the first three points of the fourth quarter on a free throw and jam to cut the Thunder's lead to 73-69.
Westbrook ended Atlanta's 11-0 run with a jam following an offensive rebound by Nick Collison.
The Hawks stayed close as Williams had two 3-pointers in the final period. Teague and Kyle Korver also had 3s in the final period for Atlanta.
Durant slowed Atlanta's comeback attempt when he dominated a sequence on both ends of the floor, blocking a shot by Smith before throwing down a jam. Smith drew a foul and Durant sank the free throw to push the lead back to 10 points at 85-75.
With about 3 minutes remaining, Durant hit a fallaway jumper. Less than a minute late, he made a spin move and then sank a 3-pointer over Korver, who was left shaking his head.
Sere Ibaka had 4 points and 14 rebounds for the Thunder.
NOTES: The Thunder assigned F Perry Jones and G DeAndre Liggins to the Tulsa 66ers of the NBA Development League. Jones, the first-round pick from Baylor, has appeared in 10 games, averaging 1.2 points and 1.4 rebounds. ... The Hawks were without G Devin Harris, who left Tuesday night's game at Washington after injuring his left foot. ... Morrow returned after missing two games with a sore back. ... Brian McCann, Jason Heyward, Dan Uggla, Kris Medlen and Freddie Freeman of the Atlanta Braves attended the game and sat with former teammate Tommy Hanson, who was recently traded to the Angels.