In almost four thrilling hours, Sinner morphed from tennis’ next big thing to the sport’s new superstar with a pulsating 3-6 3-6 6-4 6-4 6-3 final triumph over Medvedev on Sunday night.

Two days after showcasing his sublime skills with a seismic semi-final take-down of 10-time champion Novak Djokovic, the 22-year-old Italian delivered a display full of heart and will to claim his maiden grand slam crown.

“It is obviously a huge tournament for me,” Sinner said after becoming the first Italian to win the Open and also the youngest champion since Djokovic in 2008.

“I want to thank everyone for making this so special.

“My team there, everyone who is in this box, also working from home who works with me, we are trying to get better every day.

“Even during the tournament we tried to get stronger, trying to understand every situation a little bit better so I’m so glad to have you there supporting me, understanding me, which sometimes is not easy because I am still a little bit young sometimes.”

Indeed, Sinner’s Australian super-coach Darren Cahill repeatedly urged his special charge to “weather the storm” as Medvedev raced through the first two sets to take a stranglehold on the match.

And Sinner duly delivered as the Russian world No.3 endured a painful case of deja vu on Rod Laver Arena.

Two years ago, Medvedev squandered a two-sets-to-love lead in a crushing finals loss to Rafael Nadal at Melbourne Park.

Now lightning has struck twice with Medvedev sure to be haunted for years about his latest collapse, albeit entirely understandable.

The tennis ironman had toiled for an extraordinary 20 hours and 33 minutes just to make the title match and was bidding to join Djokovic as only the second player in the 56-year Open era to twice recover from two sets down to win a grand slam tournament.

Sinner, though, proved a bridge too far for Medvedev in the first AO final since 2005 not involving any of the sport’s big three of Djokovic, Nadal or Roger Federer.

Fourth-seeded Sinner entered the final as the hottest player on the planet.

His semi-final success over Djokovic ended the tennis star’s 33-match, six-year winning streak on Rod Laver Arena and appeared to signal the changing of the guard.

And so it proved, eventually after a titanic final duel in which the world No.4 had to pull out all stops to prevent Medvedev from capturing an elusive second major.

After not offering Djokovic a single break-point opportunity for the first time in the Serb’s illustrious 415-match grand slam career, Sinner’s serve faltered just two games into the title match.

Setting the tone early, Medvedev broke the Italian in the fourth game en route to taking the opening set in near-flawless fashion.

The Muscovite continued playing lights-out tennis in the second to take a stranglehold on the match.

Almost inevitably, though, in a grand slam featuring a record-equalling 35 five-set battles, the final took a dramatic twist.

Medvedev, almost out of the blue, dropped serve at 4-5 in both the third and fourth sets to set up a nerve-wracking decider.

And it was Sinner who prevailed, breaking Medvedev for a fourth time in the sixth game of the fifth set, then holding form to seal victory after a drama-filled three hours, 44 minutes.

Medvedev was gracious in defeat, despite suffering a fifth loss from his six grand slam final appearances, congratulating Sinner as a most worthy champion.

“He showed again why he deserves it,” he said.

Sinner said winning his first slam felt surreal.

“It feels great. I just have to process it, I guess,” he said.

“It has been a hell of a journey until now, even if I’m only 22.

“My parents, they always gave me the belief that I can do it in one way but in the other way they always kept zero pressure on myself.

“I had pressure when I started to play the first professional tournaments because I didn’t want them to pay for my things.

“But from that moment I had my own money to provide for my team and that for me was a game changer.”

AAP