Novak Djokovic won a record-tying sixth Key Biscayne title and his third in a row Sunday, beating Kei Nishikori 6-3, 6-3 in the Miami Open final.

The top-ranked Djokovic improved to 28-1 this year. His only loss came when he retired during his quarterfinal against Feliciano Lopez in Dubai with an eye infection.

Djokovic won his 28th ATP Masters title, breaking the record he shared with Rafael Nadal, and won both Indian Wells and the Miami Open for the third year in a row. He didn't lose a set in the tournament and tied Andre Agassi's record of six men's titles at Key Biscayne.

The No. 6-seeded Nishikori lost to Djokovic for the sixth consecutive time and was doomed by an erratic serve. He double-faulted five times, and Djokovic repeatedly pounced on his second serve to break five times.

The weather was less oppressive than in recent days, with highs only in the 70s, but Djokovic made sure the match didn't become an endurance test. He broke in three of Nishikori's first four service games, dominating rallies in part because Nishikori's shots lacked the precision of earlier matches.

Nishikori required treatment from a trainer on his left thigh late in the second set, but his bigger problem was his opponent.

Djokovic grinned and waved when a flock of pelicans flew overhead during his final service game, and that only briefly delayed the championship ceremony. When Nishikori shanked his final shot, Djokovic celebrated with a leg kick and an upper cut, and lovingly patted the court that has brought him much success.

Djokovic earned $1.03 million — the same as women's champion Victoria Azarenka. After winning Indian Wells two weeks ago, Djokovic caused a stir when he said men should earn more prize money than women because they draw larger crowds.