Nadal moved within slam trophy of Roger Federer's record men's haul after outlasting Medvedev 7-5 6-3 5-7 4-6 6-4 in New York on Sunday.
Contesting his maiden major final, Medvedev was staring at a straight-sets defeat before the fifth seed produced a stunning rally at Flushing Meadows.
But Nadal withstood Medvedev's comeback to prevail after almost five hours on court inside Arthur Ashe Stadium, where fans were brought to their feet in appreciation.
New York....I ❤️ you!!!! Congrats to @RafaelNadal he is an amazing champion. For me...these two weeks have been crazy, exciting, and humbling! But I love your energy and can’t wait to be back next year! @usopen pic.twitter.com/tbcIcmVc5c— Daniil Medvedev (@DaniilMedwed) September 9, 2019
Nadal was reduced to tears after closing in on Federer's grand slam tally and Medvedev heaped praise on the 33-year-old Spaniard afterwards.
"I just want to congratulate Rafa – 19th grand slam title is something unbelievable, outrageous," Medvedev said during the trophy presentation.
"I want to congratulate him and his team, you guys are doing an amazing job, the way you are playing is a big joke, it's very tough to play against you and you know when I was looking on the screen and they were showing number one, number two, number 19, I was like, 'if I would win, what would they show?'
"Again, what you've done for tennis in general I mean, I think 100 million kids watching you play want to play tennis and it's amazing for our sport, thank you and congrats again."
Medvedev – the villain throughout the season's final slam in the Big Apple – emerged from the jaws of defeat to almost pull off one of the greatest comebacks.
After clawing his way from a break down in the third set to prolong the final, Medvedev then saved two match points in the ninth game of the decider before Nadal eventually slumped to the floor in celebration.
Asked how he turned it around, Medvedev replied: "To be honest in my mind I was already [thinking], 'OK, what do I say in the speech? It's going to be soon, in 20 minutes, losing in three sets in the first final, trying to give a fight but not really, so I was like OK, anyway, I have to fight for every ball and I have to see how it goes' and it went far, but unfortunately didn't go my way.
"I want to talk about you guys [the crowd]. I know earlier in the tournament I said something kind of in a bad way and now I'm saying it in a good way, it's because of your energy guys that I was here in the final. Tonight is going to be always in my mind because I played in the biggest court in the tennis world and in the third set where I was already thinking which speech should I give, you guys were pushing me to prolong this match because you want to see more tennis and because of you guys I was fighting like hell.
"As I said, it's electric. You were booing me for a reason, I never said that it was not, but you guys see that I can also change because I'm a human being, I can make mistakes, and again thank you very much from the bottom of my heart."