Djokovic lost to Roger Federer in the final that year but, with the world number one knocked out by Tomas Berdych on Thursday, the second seed assumed the favourite's mantle.
So easy had the Serbian's progress been until this point, it was difficult to tell how well he was playing.
Djokovic had seemed out of sorts at Wimbledon and the Olympics, where Del Potro beat him to the bronze medal, but he showed on Arthur Ashe Stadium he is back to the form that brought him three grand slam titles last season.
The first set was a bit of a procession as Del Potro struggled to find his rhythm on his huge groundstrokes but the second was tennis of the highest order.
There was time for one last hurrah in the third set as Del Potro chased down a Djokovic volley and drilled a backhand winner, with his momentum leaving him standing on the advertising hoardings as he soaked up the crowd's adoration. But three points later the match was over, Djokovic clinching victory after three hours and six minutes.