With the win, the Serbian superstar will go on to meet Britain's Andy Murray Monday for the Grand Slam event's 2012 crown.
The second-seeded Djokovic was trailing Ferrer 2-5 in the first set when the match was suspended Saturday amid windy, rainy conditions at Flushing Meadows. Djokovic seemed rattled by the strong winds buffeting the court.
But he completely turned it around when the match resumed Sunday morning, finishing out a 2-6, 6-1, 6-4, 6-2 victory.
Djokovic collected his initial U.S. Open title last year when he defeated Spain's Rafael Nadal in the final, avenging a finals loss to Nadal in 2010.