Djokovic declared Ramos "shouldn't have pushed Serena to the limit" when asked about Williams in his press conference.
With this win, he has equaled Pete Sampras's mark of 14 Grand Slams.
'I don't know the answer.
Even Del Potro accepts that the odds are on Djokovic's side.
"Novak has everything to make records in this sport", he said.
Djokovic had never gone through an extended absence until 2017, when he sat out the second half of the season because of elbow pain that had plagued him for more than a year.
"But at the same time there was always part of me that imagined and believed and hoped that I can get back on the desired level of tennis very soon".
Djokovic, the sixth seed, tamed the Argentine big artillery 6-3, 7-6 (4), 6-3 in three hours and 15 minutes, here on Sunday, Xinhua news agency reported. He and his boisterous band of friends from Tandil, whose vocal backing ensured there was a terrific mood every time Del Potro played, brought smiles to faces time and time again.
"Of course, I'm sad because I lost but I'm happy for Novak and his team".
He needed four sets to get past 41st-ranked Hungarian Marton Fucsovics in the first round and another to get past 61st-ranked American Tennys Sandgren in the second.
All that frustration was washed away when he struck the overhead victor to clinch victory over Del Potro, Djokovic falling to his back, arms and legs spread savouring the moment. Three times, Djokovic steeled himself. The roof made for pleasant conditions Sunday, when temperatures outside reached only a high of 68 degrees F, or 20 degrees C.
The victory will also boost Djokovic to No.3 in the world rankings behind Nadal and Federer.
They led the cries of "Ole, Ole, Ole, Ole, Delpo, Delpo", most notably in the gripping and decisive second set.
"I want to say Pete, I love you, you're my idol", said Djokovic of Sampras. I've been during all my career learning with Novak, Roger, Rafa, seeing them winning these events very often. "It will be in the heart for the rest of the life".
Djokovic enjoyed the atmosphere and didn't mind the chants of "Ole", either. Why?
"This might sound amusing, but my nickname is Nole". "When they shout Ole, Ole, Ole, Ole, that's what I hear". It takes a lot of effort to actually stay poised in this moment.
Just when it looked like Djokovic would stay calm and take it to Del Potro, the Argentine fought back hard and how.
In the category that it doesn't matter how old one is, but rather how young they feel and can perform, the 31-year-old Djokovic is the ninth consecutive player over-30 to win the men's title at a Slam. Too [far] ahead of him with the Grand Slams.
After taking just two points off Del Potro's first three service games, Djokovic pounced to break for 5-3.
Del Potro was looking at having to become the first man since Pancho Gonzales in 1949 to win the USA title from two sets down.
Juan Martin del Potro believes Novak Djokovic can end his career as the most successful Grand Slam title victor, surpassing Roger Federer's current mark of 20.
His performances at the All England Club indicated he was back close to his best and he has shown the same shot-making, stamina and steeliness at Flushing Meadows. To her enormous credit, Osaka wasn't awed by the stage.
The crux of the match came midway through the second set.
He broke serve four times while an under-par Nishikori saved 13 of the 17 break points he faced and committed 51 unforced errors.
Djokovic's strength lay in his returns. Djokovic puffed out his cheeks, knowing the job was virtually done. 1 and 2, respectively, while Germany's Angelique Kerber climbed one place to 3. And it all started with Djokovic getting erked by crowd reaction and constant singing for Del Potro.