Astonishing, phenomenal, compelling, the Centre Court clash stretched to four hours and 44 minutes, knocking the 1989 last-four clash between Boris Becker and Ivan Lendl out of future record books.
Despite a mammoth fight from Del Potro, world number one Djokovic came out on top to mean only Andy Murray or Jerzy Janowicz can deny him a second Wimbledon title.
Towering Argentinian Del Potro impressively fought back after Djokovic edged the first set and repeated the trick to take the match through to a deciding set.
Djokovic eventually eked out a 7-5 4-6 7-6 (7/2) 6-7 (6/8) 6-3 victory to put a seventh grand slam crown within striking distance.
Djokovic said: "It was one of the best matches I have been involved with. One of the most exciting, definitely.
"It was so close, really. I couldn't separate us except when I was 2-1, a set up and a break, but I dropped that serve."
Former US Open champion Del Potro was bidding to get back in a grand slam final for the first time since his run in New York, and Djokovic knew he was facing a scrap.
"But, look, that is why he is a grand slam champion. That is why he is right at the top because every time he is in a tough situation he comes up with some unbelievable shots," Djokovic told the BBC.
"I didn't think I played badly when I was match point up in the tie-break, I just maybe should have stepped in and been more aggressive.
"But credit to him for fighting and I am just very proud to go through."
Coming into the semi-final, neither man had dropped a set in the tournament and it showed from the outset.
Aside from heavy strapping, Del Potro was showing few signs of the knee injury that resurfaced early in his quarter-final with David Ferrer.
The Argentinian's rocket of a forehand was causing Djokovic problems, but the top seed turned it on decisively against the serve in the 12th game just as the opening set looked poised to be decided on a tie-break.
Many would have faded away at that point, but not Del Potro.
The 2009 king of Flushing Meadows had to be at his gutsy best to recover four break points in the sixth game of the second set, and that determination immediately reaped rewards.
The noise on Centre Court ratcheted up a few notches as the 24-year-old Argentinian returned a seemingly impossible drop shot, putting him on course to break Djokovic's serve for the first time in the match and go on to take the second set.
The top seed was looking tighter than usual and was making more unforced errors than in any of his previous matches this fortnight.
On the other side of the net Del Potro was playing solidly and earned two break points in the seventh game of the third set. He mocked himself, much to the crowd's amusement, when he failed to convert the first, but roared when he fluffed his lines the second time.
It allowed Djokovic to hold serve but he was struggling to break down his opponent, whose forehand was causing the Australian Open champion to slip and slide.
Del Potro's game looked like it would be thrown off course at just the wrong time. Djokovic secured three set points in the 12th game of that third set, only for Del Potro to come storming back and force a tie-break.
A slight dip from Del Potro when he needed to stay focused allowed Djokovic to take the set 7-6 (7/2) and regain control of the match.
It looked all over for the world number eight when Djokovic broke for 4-3 in the fourth set.
Yet again, though, Del Potro showed incredible fighting spirit to hit straight back as the set went to another tie-break.
This time the 6ft 8in man from Tandil produced more heroics, recovering from two match points down to take the match into a deciding set.
Nobody inside Centre Court could quite believe it and Djokovic had to dig deep in the fifth game to deny Del Potro, who was receiving attention during the breaks.
Del Potro saved a break point in the following game, with some sloppy play from the world number one helping.
There were some astonishing rallies but Del Potro was visibly tiring and he allowed Djokovic two break points, the Serbian converting the second for 5-3.
It allowed the top seed to serve for the match and, having saved a break point, he secured his place in the final, in a match that comes its finale was 43 minutes longer than the Becker-Lendl clash.
A warm embrace at the net between the players was a sign of respect, as was the standing ovation from all around Centre Court as the warriors departed the scene of their great battle.