Novak Djokovic won his fourth Key Biscayne title, while Rafael Nadal failed again trying for his first.

Djokovic dominated from the start and closed out the victory by winning a remarkable exchange to beat Nadal 6-3, 6-3 Sunday in the final of the Sony Open.

Nadal fell to 0-4 in finals at Key Biscayne, one of just three ATP Masters 1000 events he has yet to win. Only six-time champion Andre Agassi has won the men's event more than Djokovic.

Djokovic erased the only break point he faced, committed just 15 unforced errors and won a scrambling, 30-shot rally on the final point.

He completed a March sweep after beating Roger Federer in the final at Indian Wells two weeks ago. Even so, Nadal will remain ranked No. 1 and Djokovic No. 2.