NEW YORK (AP) — Hard to believe this is the same Rafael Nadal who was at home during the U.S. Open a year ago, nursing a bad left knee.

Hard to believe this is the guy sent packing in the first round of Wimbledon in June, losing against someone ranked 135th.

Looking fit as can be, and tough as — maybe even better than — ever, the No. 2-ranked Nadal pulled away from No. 1 Novak Djokovic 6-2, 3-6, 6-4, 6-1 on Monday in a taut, tense U.S. Open final for his 13th Grand Slam title.

They started in sunlight and finished at nighttime, a 3-hour, 21-minute match.

There was no quit in either of them, during points that lasted 15, 25, even more than 50 strokes.

This was their 37th match against each other, the most between any two men in the Open era, and third head-to-head U.S. Open final in the last four years. Nadal beat Djokovic for the 2010 title, and Djokovic won their rematch in 2011.

He improved to 22-0 on hard courts and 60-3 overall in 2013 with nine titles, including at the French Open, which made him the first man with at least one Grand Slam trophy in nine consecutive seasons. The 27-year-old Spaniard’s total of 13 major championships ranks third in the history of men’s tennis, behind only Roger Federer’s 17 and Pete Sampras’ 14.