The Italian fourth seed remained composed even after losing his first set of the tournament against the reigning king of Rod Laver Arena, ultimately winning 6-1, 6-2, 6-7 (6/8), 6-3 to secure his first-ever Grand Slam final appearance.
Sinner will now await the winner of the match between third seed Daniil Medvedev and sixth seed Alexander Zverev in Sunday's title showdown.
"It was a very tough match," Sinner acknowledged. "I started off really well. He seemed to be struggling in the first two sets. I sensed that he wasn't feeling his best on the court, so I just kept pushing."
Ten-time champion Djokovic, who hadn't tasted defeat at the Australian Open since 2018, was aiming to claim a record-breaking 25th Grand Slam title. However, Sinner shattered those aspirations in spectacular fashion.
Djokovic appeared helpless against his 22-year-old opponent from the start of the match. Moreover, his own performance was far from his usual precision, committing 29 unforced errors in the first two sets, in stark contrast to Sinner's eight.
The 36-year-old Serbian lacked his customary consistency, while the cool-headed Sinner, unfazed by the fact that Djokovic had never lost a semifinal at Melbourne Park, swiftly established a 3-0 lead.
The Italian broke Djokovic's serve once again in the sixth game, securing the set when Djokovic hit a forehand long.
At the beginning of the second set, the volume in the center court increased, and Djokovic regrouped with a convincing hold of serve. Nevertheless, his error count continued to rise, and Sinner, who had defeated Djokovic in two out of their three previous encounters, broke Djokovic's serve once again in the third game, maintaining a firm hold on the match.
Amidst a pause at 5-5, 40-40 in the third set for medical attention to a fan in the crowd, Djokovic regained his composure and held serve, leading to a tiebreak. Djokovic initially took the upper hand, but Sinner fought back to earn his first match point, only to falter with a forehand into the net.
Djokovic capitalized on the opportunity to claim the set, raising his clenched fist in triumph to the crowd.
However, Djokovic's serve came under renewed pressure in the fourth set, and he succumbed, allowing Sinner to take a 3-1 lead. Sinner retained his composure to close out the match, signaling the end of an era at Melbourne Park.