UFC 221 featured half of an interim UFC Middleweight Championship fight, that actually ended up being not a title fight at all.
Yoel Romero defeated Luke Rockhold via a vicious third round knockout after a close two opening rounds. However, due to missing weight, Romero wasn't able to win the same title Rockhold was.
You can see an excerpt of Fightful.com's live coverage below.
Round Three: The round begins with Rockhold keeping Romero at bay by throwing jabs, Romero follows Rockhold around the Octagon while eating strikes. Romero destroys Rockhold with an overhand left followed by one more on the ground and the referee jumps in.
Official Result: #1 Yoel Romero def. #2 Luke Rockhold by KO via strikes (1:48, R3)
Only Rockhold was eligible to win the interim UFC Middleweight Championship. Romero, who took the fight on short notice, was unable to make the 185 pound limit, and was ruled ineligible to capture the championship.
Current UFC Middleweight Champion Robert Whittaker was originally scheduled to headline UFC 221 against Rockhold, but was ruled out and replaced by Romero after suffering from a serious stomach infection.