They circled the globe on private jets, in the most expensive media tour the UFC has ever funded. After a rib injury delayed the fight in July, talk continued until they fought in December. It remains the most thorough buildup to a championship tilt in UFC history.
It also remains the shortest championship tilt in UFC history. A mere 13 seconds in, McGregor landed a counter left hand as Aldo came forward with a hook -- and that was that.
In his comments afterward, McGregor credited precision and timing for the knockout. Aldo believes it was something else: luck.
"Obviously, there was luck involved," Aldo told ESPN.com, through an interpreter. "He was lucky to get that shot in right away. If my punch would have landed a little lower, then he would have been the one on the mat. So, there was definitely luck involved."
Aldo (25-2), who fights out of Rio de Janeiro, is anxious to prove as much against McGregor by defeating him in a rematch, but he'll have to wait for that opportunity. Despite his requests for an immediate rematch, the UFC has booked Aldo to an interim title fight against Frankie Edgar (20-4-1) at UFC 200 on July 9.
The UFC decided to create an interim title because of McGregor's willful absence from the division. After knocking out Aldo in December, McGregor decided to move up in weight and challenge Rafael dos Anjos for the lightweight championship. Those plans fell apart, however, when dos Anjos suffered an injury and was replaced on short notice by Nate Diaz.
Diaz (19-10) ended up submitting McGregor (19-3) at UFC 196 last month. Rather than return to 145 pounds to defend his title, McGregor opted to rematch Diaz in a welterweight fight. That bout will headline UFC 200.
Aldo, who defended his UFC title seven times from 2011 to 2015, said he doesn't care about an interim title but sees it as a way to guarantee a rematch against McGregor later this year.
"Obviously, I'm not happy that I didn't get a rematch," Aldo said. "It's disrespectful due to everything I've done. I'm deserving of a rematch and it's not just me who says that. Everyone has been coming up to me, asking when the rematch is going to happen. But I'm an employee for the UFC, and this is what they decided. What can I do?
"Conor is going to have to come back [to the division] to fight me. I expect that. Everybody expects that."
The UFC actually did offer Aldo a rematch in late February, after dos Anjos withdrew from UFC 196. Aldo said he couldn't be ready within that time frame, however, and opted to turn the short-notice fight down. That decision drew some criticism, as Aldo had previously stated he would fight McGregor "at any time, anywhere."
Aldo said he had no regrets about turning down the fight and expects to face McGregor before the end of the year.
"The fight I turned down, I was traveling and doing charity work," Aldo said. "After being the champion for so long, I deserve the respect of having a fight set and not fighting on one week's notice. I'm not a guy who just fills in to save an event. I was the champion for a long time.
"Like I've been saying, by the end of the year, the belt will be mine again and he'll go back to being what he was -- which is nothing."