Oliveira knocked out Michael Chandler in the main event of UFC 262 to win the 155-pound championship - which was vacated by previous titleholder Khabib Nurmagomedov in March.
Despite being just 31 years old, his bout with Chandler marked Oliveira's 28th UFC contest. The Brazilian submission ace debuted for the promotion all the way back in August 2010. At that time, McGregor was a four-fight novice, competing on the regional scene in Ireland.
'Notorious', however, was only focused on the future when he tweeted following Oliveira's win.
McGregor wrote: "Congrats to Olivera on becoming the 11th UFC lightweight champion. Wonder who Twelve is..."
The sport's biggest star is set for a third fight with his long-time rival Dustin Poirier on July 10, but McGregor clearly has his sights set on the new champion should he emerge victorious in that bout.
Oliveira would be no easy task for McGregor, though. 'Do Bronx' showed immense durability to get the job done against Chandler, surviving a big early onslaught from the American.
Oliveira had his moments in the five first five minutes, too, however, nearly locking in a brutal submission early doors, only for Chandler to escape. In truth, though, he appeared to be only one clean shot away from defeat at the end of the first round, with the American in full control.
Despite looking in trouble, it took just 19 seconds of the second round for Oliveira to turn things around completely. Oliveira floored Chandler with a vicious left hook, before finishing him with strikes to take the title.
It was a shocking ending to one of the wildest championship fights in UFC history.
It was a career-defining performance for Oliveira, who broke the UFC record for most finishes with his victory, recording the 17th win inside the distance for the promotion.
If McGregor gets past Poirier at UFC 264, then he will be able to demand any opponent he chooses, including new champion Oliveira.
Whether he can defeat the submission specialist and become the 12th UFC lightweight champion, though, remains to be seen.
On the evidence of Saturday night, Oliveira will be a tough night's work for anyone.News Now - Sport News