Jon Jones made history when he defeated Dominick Reyes earlier this year, but their meeting was not without controversy.
Light-heavyweight king Jones won his 14th UFC title fight in the February bout in Houston, one more than Georges St-Pierre's tally of 13.
But the verdict of the judges to score the bout unanimously for Jones was one that rankled with Reyes - and many fans felt the 30-year-old had a valid point.
So, while all-time great Jones scored the victory, there is a school of thought that he still has questions to answer against Reyes.
That is why the two are the subject of the fourth in our series on UFC rematches we want to see.
WHAT'S THEIR STORY SO FAR?
Prior to the bout with Reyes, Jones had been unconvincing in a split-decision win over Thiago Santos last July.
He did not exactly fire on all cylinders early doors against Reyes either, with Jones' decision to try and stay on his feet, rather than go for takedowns, a surprise to many.
Jones eventually took Reyes to the mat in the fourth, then came out firing in the fifth as Reyes seemingly thought all he had to do was survive to earn the win.
It was a surprise, therefore, when Jones was scored a 48-47, 48-47, 49-46 victory by the judges.
WHY DO WE WANT TO SEE THEM GO AGAIN?
Mainly because it feels like there is another chapter to this story.
Reyes will feel he is deserving of a rematch and most would agree; UFC president Dana White has openly said he likes the idea of the two going up against each other again.
At light-heavyweight, there is not exactly a plethora of options around for Jones - why not dance again with Reyes, then?
HAVE THEY FOUGHT SINCE?
No. Given only three months has passed since their first bout, neither has been in action.
Any plans to get back in the Octagon have also been complicated by the coronavirus pandemic, which saw UFC temporarily suspend operations before resuming behind closed doors.
WILL IT HAPPEN?
As is so often the case in the fight game, the money needs to be right.
Jones has said he is willing to give Reyes another shot at the belt for the right price. There is certainly a desire from Reyes, while a rematch has the backing of White. The outlook suggests there is a good chance it unfolds at some stage in the future.
WHO WOULD WIN?
It is a tricky one to call. However, an athlete with the fight IQ of Jones - one of the undoubted greats - is unlikely to make the same mistakes second time around.