The world number three, narrowly beaten by Spain's Rafael Nadal in Friday's semi-final, broke early in the first set and was rock solid throughout.
Blake, who ended Swiss world number one Roger Federer's run in the singles on Thursday, made a scrap of it in the second set and Djokovic became rattled, smashing his racket at 4-4.
However, the Australian Open champion went 6-4 ahead in the tiebreaker and fell to his knees in joy when Blake put a backhand into the tramlines.
The Serb celebrated by throwing most of his kit, including his rackets and shirt, into the crowd after holding aloft the Serbian flag.
Photograph: Getty Images