There are areas to improve on for Djokovic despite the comfortable scoreline - he hit 10 double faults and 40 unforced errors, along with putting just 47% of his first serves into play.

Playing under a closed roof on Arthur Ashe Stadium, Djokovic needed 33 minutes to win the opening set, going a double break up before serving out the opener.

Despite the positive start, the four-time US Open champion gestured angrily towards his player's box throughout the match and appeared to be bothered by the humid conditions.

He was still wearing the knee support that he has used since having surgery on the area in June.

After conceding serve early in the second set, Albot managed to break back and level at 2-2 before Djokovic won the next four games.

The world number 138 kept Djokovic at bay for slightly longer in the third set, fending off five break points, but the reigning champion finally broke through the resistance at 3-3 before wrapping up victory as the clock struck midnight in New York.

"I love playing night sessions but maybe not this late," Djokovic said in his on-court interview.

"Nevertheless it was great fun and I want to thank everyone for staying."

The victory also allowed Djokovic to set another record - the most wins (78) by a male player on Flushing Meadows' main showcourt.

"It's the biggest stadium. Definitely the loudest we have in the history of our sport," Djokovic added.

"The night sessions are the best in the world on Arthur Ashe."