Durant made 5-of-7 from 3-point range, boosting the Thunder to their third win in four games. Jeff Green had 19 points, Nick Collison added 18 and Russell Westbrook handed out a career-best 15 assists.
Andre Iguodala led the 76ers with 28 points.
Philadelphia announced earlier in the day it had reached a contract agreement with Allen Iverson, who spent the first decade of his career with the 76ers. Iverson, who had said he was retiring last week after being released by Memphis, will be in uniform next Monday against Denver.
Philadelphia has lost eight games in a row.