Westbrook finished 12-for-13 from the free-throw line -- a season high in attempts and makes -- to lead the Thunder's assault on the charity stripe. Oklahoma City went 25-for-33 from the line and has 73 attempts over the last two games. George scored 42 points two nights earlier. He added eight rebounds, five assists and shot 54.5 percent from the field.
Harrison Barnes led Dallas with 22 points, Yogi Ferrell added 18, and Dennis Smith Jr. scored 15 points for the Mavericks (2-12), who have lost eight of their last nine games.
Coming off its best shooting performance of the season, Oklahoma City (6-7) started the game just 3-for-12 but rallied to shoot 44.1 percent in the first half. The Thunder had just two assists in the first quarter but never trailed by more than four points before halftime.
Westbrook hit 3-pointer with 4:37 to play in the third quarter to push the Oklahoma City lead to 13 points, forcing a Dallas timeout. The Thunder, which has won seven of its last eight regular-season games against the Mavericks, led by 16 points to start the fourth quarter following a season-best 39 points in the third quarter.
Adams missed his second straight game with a right calf contusion, and Anthony was a late scratch due to back soreness.
Dallas returns to action Tuesday against San Antonio after losing the second half of a back-to-back for the fourth straight time to start the season. Oklahoma City closes out a three-game homestand against Chicago on Wednesday.
NOTES: Thunder F Jerami Grant started in place of Carmelo Anthony, scoring 10 points in his fifth career start. ... Dallas F Harrison Barnes, the Mavericks' leading scorer this season, appeared in his 400th career game Sunday. ... Mavericks F Dirk Nowitzki was issued a flagrant foul midway through the second quarter and received a technical after arguing the call. ... Thunder F Patrick Patterson scored seven points in the first half to set a season high. He came into the game averaging just 2.3 points per game and had never scored more than six. ... Thunder G Josh Huestis scored a career-high nine points; six in the second quarter. ... Mavericks reserve G Devin Harris missed Sunday's game with bruised ribs.