Oklahoma City used a 17-5 run to go up 45-35 on Martin’s 3-pointer with 3:09 left in the first half.
The Suns with 4 minutes, 15 seconds without a point in the early stages of the Thunder outburst.
Shannon Brown scored on a drive to the basket and was fouled for a 3-point play with 1.8 seconds left to cut Oklahoma City’s lead 51-45 at the break.
Westbrook scored 16 on 7 of 11 shooting to lead the Thunder in the first half, while Durant scored 14 and Kevin Martin 12.
Brown scored 12 in the first two quarters. Gortat had 12 points and 10 rebounds in the first half.
Westbrook’s 15-footer capped a 6-0 spurt that put the Thunder ahead 66-52 with 6:24 to play in the third quarter.
Notes: Boxer Floyd Mayweather Jr. had a courtside seat. Kareem Abdul-Jabbar was in attendance with former Suns owner Jerry Colangelo, now head of USA Basketball. ... Oklahoma City has won five straight in Phoenix, tied with Miami for longest active streak at US Airways Center. ... Dudley missed his second straight game. O’Neal was a game-time scratch.