One more victory will give the 34-year-old Djokovic the first calendar-year Slam since Rod Laver accomplished it 52 years ago.
Novak Djokovic will play Daniil Medvedev to try and complete the first men's singles calendar-year Grand Slam since 1969 after defeating Tokyo Olympic champion Alexander Zverev in US Open semi-finals.
Top-ranked Djokovic outlasted the German fourth seed 4-6, 6-2, 6-4, 4-6, 6-2 to reach Sunday's championship match at Arthur Ashe Stadium against Russian second seed Medvedev.
"I'm going to treat the next match like it's the last match of my career," Djokovic said.
"There s only one more match left. All in. Let's do it," Djokovic said. "I'm going to put my heart and my soul and my body and my head into that one."
Djokovic seeks his fourth career US Open title and his 21st overall Slam crown, which would lift him one above the all-time record he shares with Rafael Nadal and Roger Federer, both absent with injuries.
"These are the moments we live for," Djokovic said. "These are the kind of unique opportunities we dream of when we are looking for motivation."
Australian legend Laver, 83, was in the stands to watch as Djokovic took a measure of revenge for Zverev, 24, beating him in an Olympic semi-final, denying Djokovic's bid for a "Golden Slam" with a Tokyo gold medal.
"I knew coming onto the court it was going to be a great battle," Djokovic said. "Alexander is a big champion. He's someone I admire on and off the court."
Medvedev, the 2019 US Open runner-up, defeated Canadian 12th seed Felix Auger-Aliassime 6-4, 7-5, 6-2 to reach his third career Slam final.
"I don't think I played my best today but I'm really happy to be in the final," Medvedev said.
Djokovic is the oldest US Open finalist since Andre Agassi at 35 in 2005 and could be the oldest US Open champion since Ken Rosewall at 35 in 1970.
By beating Zverev, Djokovic matched Federer's all-time record of 31 men's Slam final appearances. Djokovic is 20-10 in major finals.
The final is a rematch of February's Australian Open final won by Djokovic in straight sets. Medvedev trails Djokovic 5-3 in their all-time rivalry.
"If I can make this, I'll probably be in the history books a little bit somewhere like not letting him do this," Medvedev said. "But I don't really care about it. I think it's more about him, that it affects him.
"I'm just going to throw it everything and I'm definitely not going to be thinking about Grand Slam or whatever."
Djokovic has won 27 consecutive Slam matches, three shy of his all-time record streak from 2015 and 2016 when he won all four major titles in a row.
Zverev, last year's US Open runner-up, saw his 16-match win streak end.
In the fifth set, Djokovic broke after an extended rally with a forehand passing winner to 2-0 and Zverev swatted back-to-back forehands long to go down 4-0. Djokovic broke again in the eighth to book his date with history after three hours and 34 minutes.
Djokovic double-faulted away a break in the ninth game and Zverev held to claim the first set in 36 minutes.
Having dropped the first set for the fourth consecutive match, Djokovic dominated the second, never facing a break point.
A 10th-game groundstrokes battle in the third set saw a 53-shot rally ended by a Zverev forehand winner to save set point and draw a roar from the crowd, but Djokovic hit an overhead smash on the next point for the break to capture the set.
In the fourth, Zverev broke to 2-1 with a forehand winner and held from there.
Auger-Aliassime lost two set points and was broken in the ninth game of the second set and Medvedev broke again at love on the way to taking the set to seize command of the match.
"I knew I had to do everything at my best because at that point in the match I knew I could break him mentally and that's what happened," Medvedev said.
In all Medvedev took 11 of the final 13 games, ending matters with an overhead smash after two hours and four minutes.
"I had to play my best level and even better if I wanted to get a chance to win," Auger-Aliassime said. "I didn't do it long enough. Overall Daniil was the better player."