Into the third set and Sinner was beginning to find his spots, in sharp contrast to Medvedev looking increasingly beleaguered from his marathon man exploits this fortnight.
Prolonging the rallies, striking with more conviction, Sinner was hustling. Having 'weathered the storm' to snatch away set, it was time for the 22-year-old to dictate play.
On the front foot, Sinner's serving stats rocketed up, Medvedev's dropped, the Italian was spreading the play and biding his time.
Fourth set in the bag, the momentum was well and truly with Sinner in the decider. The No.4 seed prevailing in a 41-shot rally as the pick of the bunch in a catalogue of draining duels.
By this point Medvedev had accumulated 24 hours on court in Melbourne, whereas Sinner was relatively fresh and pinged a backhand pass, then crunched a forehand winner cross court, to steal the pivotal 4-2 break.
It was Sinner, falling to the court in a star shape, realising he was a Grand Slam champion.