The 31-year-old produced a ruthless display as he recorded a 6-3, 7-6, 6-3 victory at Flushing Meadows in New York.

The triumph for the sixth seed saw him complete the Wimbledon-US Open double for a third time and he remains only the eighth player to have achieved the feat in a calendar year.

Djokovic has also closed the gap on great rivals Roger Federer and Rafael Nadal, who have 20 and 17 Grand Slam titles to their name respectively.

Defeat for Argentina's Del Potro ended his chances of claiming a second US Open crown following his victory in 2009 but still capped a remarkable run after he nearly quit the sport in 2015 because of ongoing injury problems.

"When I had surgery on my elbow earlier this year I could truly understand what Juan Martin was going through with his surgeries during the two or three years that kept him away from the tour," said Djokovic.

"They were difficult times, but you learn from adversity. 

"You learn when you’re down, when you have doubtful moments, when things are not working out as you want them to."

Djokovic, the 2011 and 2015 US Open champion, largely controlled proceedings in a high-quality final.

It would have come as a welcome relief for organisers and the sport in general following the controversy which overshadowed the previous day's women's final between Serena Williams and Naomi Osaka.

While the scoreline suggested a comfortable evening for Djokovic, the Serbian was still made to work hard and had to produce some of his best and most consistent tennis.

The second set tie-break proved to be the turning point as the Serbian took it and from that point on, his victory on Arthur Ashe Stadium looked inevitable.

He sealed the win with a forehand volley before going to hug a visibly-dejected Del Potro at the net.