Two and a half years have passed since they last fought, and the UFC middleweight title last changed hands.
During that time, the former champion has been fighting to get back in the title picture, while the new champion defended against all who stepped up to him.
This Sunday, it's the second chapter in their story when Ngāpuhi fighter Robert Whittaker tries to reclaim his title from middleweight champion Israel Adesanya, in UFC 271's main event.
The road back to the title
It was in front of a raucous Australian home crowd in Melbourne for the Māori-Aussie fighter where Whittaker last held the middleweight championship back in 2019.
Though he came out firing during the fight, the second round spelt the end for Whittaker when Adesanya [then interim-champion] knocked him out to become the undisputed king of the middleweights.
"The Reaper" has been humble ever since the loss, even acknowledging Adesanya is a good fighter numerous times to the media, while also getting back to his winning ways.
In that two-and-a-half years, Whittaker has bounced back and improved his fight game tremendously with a three-win fight streak over Kelvin Gastelum, Darren Till and Jared Cannonier.
At the official UFC 271 press conference today, Whittaker said he was ready to test himself with the changes he's made in his fight game when he and Adesanya throw down soon.
"I've made lots of changes in the last few years, but you can't reinvent the wheel. I've just been making slight improvements - trying to get better, try to be more diverse, and, honestly, I've put the work in. I'm excited to get in there with him and to, just, test myself.
"The rematch is just a good way for me to gauge how far I've come, or how far I've got to go and I look forward to getting in there with him."
To set the record straight about whether their next bout is personal, Whittaker admits that unlike his last fight, where he built up anger for Adesanya, he is more calm and collected.
"I think I was just venting on [Adesanya], to be honest. I was feeling the pressure from a lot of different avenues and not happy with a lot of different things, and I was angling a lot of it towards him.
"But I've let all that go. I'm pretty cool now."
Dominating the middleweight division is no easy feat. But that's exactly what the Nigerian-born New Zealand fighter Israel Adesanya has done. He's undefeated in the division, is the division's king, and has beaten all of his challengers since winning the title from Whittaker in 2019.
Adesanya's first title defence was against the man no one would dare call out, Yoel Romero. Adesanya easily beat him by unanimous decision.
Next came Brazilian fighter, Paulo Costa. Their trash talk was rampant through their media days, and he lost to Adesanya by TKO.
His third title defence saw Adesanya seal the deal with the verbal and physical jabs, getting a 50-45 point win over Marvin Vettori.
And on top of wins and sponsorship deals, including being the cover star of the UFC 4 videogame, Adesanya has now signed on the line of one of the UFC's best contracts. According to his management at Paradigm Sports, the contract is "one of the most lucrative multi-fight deals in company history."
No details have been shared about the contract but it is said that he could be the second-highest paid UFC athlete behind Irish lightweight icon Conor McGregor, who is also managed by Paradigm Sports.
'He ran through everyone till' he ran into me'
Today at the press conference, though both men were respectful, Adesanya acknowledged Whittaker's winning form... to a certain degree.
"He's [Whittaker] made a lot of improvements in his game," Adesanya says.
"From tough nationals to being the UFC middleweight champion, this guy did a lot of work and he ran through everyone 'till he ran into me, then I stopped that s***.
"But the last three fights, he has done what he's always done, he's improved, he's always been a beast. But I'm a different beast but the same animal."
It's Adesanya vs Whittaker II, UFC 271 live on pay-per-view, with the main card kicking off this Sunday from 4pm [NZ time]. At 12pm, City Kickboxing teammates battle inside the octagon as well when Blood Diamond debuts and Carlos Ulberg looks to get his first win in his second UFC fight, in the UFC Fight Pass Preliminary Card.