For many years, Djokovic has defied the aging process with his stamina and prowess.
This was the latest example – at a time when few expected it.
It appears that time is finally starting to catch up with the player aiming to become the oldest Grand Slam men's singles champion in history.
Last year was the first since 2017 – and only the second since 2010 – in which he did not win one of the sport's four major trophies.
Doubts had already been raised about his ability to withstand his best younger rivals, Alcaraz and world number one Jannik Sinner, over five sets.
Sinner's aura of invincibility was damaged at Melbourne Park last year when Sinner dominated the semi-finals to end his 33-match winning streak at this stadium.
Alcaraz then beat him in the Wimbledon final, albeit in a match that came less than six weeks after Djokovic underwent surgery on a torn kneecap.
However, Djokovic won his last encounter with Alcaraz, putting on a ferocious showing at the Olympics to take the gold that had previously eluded him.
His more patient approach in the first set on Tuesday was quickly replaced after he adjusted something in order to putt the ball away.
Using more aggression was a risk-reward strategy but necessary given his physical condition. It has paid off.
Djokovic fired 11 winners, including a powerful backhand winner on deciding point to level the match, as he successfully weaved his way through a barrage of Alcaraz's shots.
Alcaraz's service games at the beginning of the third set continued to come under heavy fire. It collapsed when Djokovic broke his opponent's serve to lead 4-2, and the third seed dropped his serve again at 5-3 after seemingly saving the situation.
Djokovic used that momentum to break serve in the first game of the fourth set, something that ultimately proved decisive.
After surviving three break points and recovering from a series of long points that sapped his energy, Djokovic held his nerve to achieve an unforgettable victory.
Regarding his readiness to play again on Friday, he said: “I am physically worried, but if I can somehow prepare physically, I am as mentally and emotionally prepared as possible.”
