Italy's 22-year-old Sinner trailed by two sets before staging a comeback to win 3-6 3-6 6-4 6-4 6-3 in his inaugural major final.

Initially struggling to match the Russian's pace, fourth seed Sinner gradually asserted himself as the contest progressed.

It was yet another disappointing moment for Medvedev, who previously squandered a two-set lead against Rafael Nadal in the 2022 final.

With Sinner's victory over 10-time winner Novak Djokovic in the semi-finals, Melbourne was guaranteed to crown a first-time champion.

Sinner secured his name on the trophy, fulfilling the talent that many had forecasted would culminate in a Grand Slam victory, following a courageous comeback in a nearly four-hour-long match.

"It feels incredible. I just need some time to fully grasp it, I suppose, experiencing it for the first time," Sinner told Australia's Channel Nine.

"It's been an incredible journey, and I'm only 22 years old," Sinner remarked.

Third-seeded Medvedev, aged 27, has now lost five out of his six major finals, including matches against Djokovic in 2021 and Nadal in 2022 at Melbourne Park.

Sinner sealed the win with a forehand winner down the line, collapsing on his back in jubilation at the baseline.

Medvedev made his way around the net to extend his congratulations before Sinner, in a show of gratitude, thumped his heart and proceeded to celebrate with his team.