A series of missed forehands by del Potro in the tiebreaker put Djokovic back on course and he finished with a flourish, taking the last three games - sealing the title on his first match point. Djokovic a two-time US Open champ and 13-time Grand Slam victor, was just that much better than Nishikori in a 6-3, 6-4, 6-2 win to reach his record-tying eighth final in NY.
Three times, del Potro was a point from breaking and earning the right to serve to make it a set apiece.
Never was that more apparent than the game that stood out on this evening: with Djokovic serving while down 4-3 in the second set. He had the upper hand in the second set tie-breaker but couldn't convert, and after fighting back from a break down in the third set he served up a double fault to give Djokovic a chance for the final break of serve.
Federer and Del Potro have had run-ins in the past.More news: Coroner recognized youngest killed in Cincinnati shooting
"We are proud to be close to these legends", Del Potro said. "But at the same time, life showed me that it takes time for good things, it takes time to really build them, for things to fall into place, so you can centre yourself, balance yourself and thrive".
The tension and fireworks of the Osaka-Williams clash were left behind during a relatively calm and composed baseline battle between two friends and familiar foes who had played each other 18 times, with Djokovic holding a commanding 14-4 edge. It was even louder because of the closed roof over Arthur Ashe Stadium to keep out the rain.
Novak Djokovic celebrates his US Open 2018 victory at the Arthur Ashe Stadium.More news: Elon Musk puffs on marijuana joint during live interview
No controversy here: Novak Djokovic is the U.S. Open men's singles champion.
After missing last year's tournament with an injured right elbow that eventually required surgery, Djokovic rubber-stamped his return the top of his game with another major title to add to his fourth Wimbledon crown in July. "But I'm happy for Novak and his team".
"I was hoping he's [Pete Sampras] going to be here tonight but I want to say 'Pete, I love you, you're my idol".
Djokovic went on to congratulate Del Potro for his achievements despite all the injury trouble and made a massively sporting gesture by saying he knew Del Potro will stand as champion at this podium one day. During the time in-between, he had four wrist surgeries, including three on his left wrist, and contemplated quitting the sport altogether.More news: Here’s What Shahid Kapoor Has Named His Son
Amidst the searing heat and disturbing humidity of NY for the past two weeks, Djokovic battled through and rose above it all to shine under the Arthur Ashe Stadium lights for the third time.