The 28-year-old acknowledged there were doubters before the fight but he put those concerns to bed.
"I'm just getting warmed up," Adesanya said. "I've still got tricks up my sleeve, just give me some time.
"I feel like I proved everybody wrong. They said 'oh, it's too soon for him, Brad Tavares is a tough dude'."
Tavares had combat sports legend Ray Sefo, the Aucklander who made his name in the K-1 kickboxing heyday, in his corner for the bout.
After a close opening frame, Adesanya took control of the contest; his superior speed, crisp striking and length was too much for Tavares to handle.
Two judges scored the bout 50-45 in favour of Adesanya, while one judge had it 49-46.
The NZ Herald scored the bout 49-46 to Adesanya.
"It was a good fight," Adesanya said. "It was just a beautiful chess match.
"I was able to flow, be in the moment and listen to my corner."
Adesanya peppered Tavares with knees and body kicks during the bout and Tavares suffered a nasty cut to his right eye during the fourth round due to an elbow from the Kiwi.
In the end, the volume of shots took its toll and Adesanya landed 127 total strikes to 46 from Tavares.
The Last Stylebender was also able to stuff the takedown attempts from Tavares, a Hawaiian now based in Las Vegas.
Considering this was his first opportunity against a ranked opponent, Adesanya looked remarkably comfortable on the big stage.
His movement proved tricky for Tavares as the Hawaiian struggled to solve the puzzle.
Despite not getting the finish, Adesanya also banked a US$50,000 'Performance of the Night' bonus for his efforts, his second of his UFC career.
As for what might be next, Adesanya said he would have some rest and asked for the winner of tomorrow's UFC 226 battle between Uriah Hall (13-8) and Paulo Costa (11-0).
Auckland lightweight Dan Hooker (16-7) will meet Brazil's Gilbert Burns (14-2) on the UFC 226 undercard.
See how the fight unfolded below.