Lots of narratives that can be attached to this game but to me Golden State going small early was the key. Playing Lee off the bench has helped as well. Kerr clearly decided having Bogut or Ezeli out there isn't worth the detriment to their spacing, and he's been validated so far.
Cleveland being utterly exhausted would be a close second though. Not the same team as in the first 3 games. When I saw "Dellavedova (fatigue) will play in Game 4" on the ticker I thought this might be coming.
Heck of a series so far, though.