Unable to play at last year’s event due to being unvaccinated against COVID-19, Djokovic had not been seen on the Flushing Meadows hard courts since his loss to Daniil Medvedev in the 2021 final.
And fans let the 36-year-old know they had missed him, showering the Serb with applause as he emerged from the tunnel onto Arthur Ashe Stadium court.
It was clear that the three-time champion had missed them as well as he embraced the cheers of a record crowd of over 30,000 that included former-US President Barack Obama and his wife Michelle.
Arriving in New York on the back of an absorbing win over his young rival Carlos Alcaraz in the Cincinnati Open final, an in-form Djokovic showed the 84th ranked Muller no mercy in what was his US Open main draw debut.
Firing on all cylinders, Djokovic broke the overwhelmed Frenchman to open the match and never took his foot off the gas, closing out the first set in 23 minutes with a thundering ace.
Djokovic broke Muller for a fourth time to open the second set and went 2-0 up before his opponent held serve for the first time, raising both hands in triumph as the crowd roared.
But the cheers would be few and far between as Djokovic closed out the second with a wicked forehand.
Muller showed more ambition in the third, taking the set to 3-3 before Djokovic took control by breaking the Frenchman twice on the way to closing out the match.
While the US Open has just got underway, Djokovic’s win guarantees he will nudge Alcaraz out of top spot when the world rankings are updated on Sept. 11.
Alcaraz, who beat Djokovic in an epic Wimbledon final in July, opens his account on Tuesday against Germany’s Dominik Koepfer.
The path to a 10th US Open final and a possible mouthwatering showdown with Alcaraz will get tougher but Djokovic had one obstacle removed from his side of the draw when Danish fourth seed Holger Rune was upset 6-3 4-6 6-3 6-2 by Spanish clay court specialist Roberto Carballes Baena.
Next up for number two seed Djokovic is Spain’s Bernabe Zapata Miralles, who was a straight sets winner over American Ethan Quinn.