Westbrook and Durant both had double-doubles for the rampaging Thunder, who now lead 3-1 in the best-of-seven play-off series, with the Warriors now facing a mountain to climb in their bid for back-to-back championships.
The comprehensive game-four victory saw Westbrook post his fifth successive double-double and 10th in 15 post-season matches via 36 points and 11 assists, while Durant chipped in with 26 points and 11 rebounds.
Despite romping to a 28-point victory in game three on Sunday, the Thunder were expected to be pegged back by the Warriors.
But the Warriors were barely given a sniff after the Thunder raced out to a 72-53 half-time lead, inspired by a 42-point second quarter.
NBA MVP Stephen Curry (19 points) and the Warriors attempted to claw their way back into the contest, closing to within nine points with less than two minutes remaining in the third quarter.
However, the Thunder were not to be denied as they limited the Warriors to just 12 fourth-quarter points, earning a commanding lead in the process.
The Warriors return to Golden State for game five on Thursday.