The headline fight of the UFC's international Fight Week in July saw the rampaging Robert Whittaker beat Yoel Romero to win the interim middleweight title.
The New Zealander won his eighth straight fight and "Fight of the Night" honours with a comprehensive, unanimous decision win.
Gunnar Nelson headlined the UFC's return to Scotland, but was stopped in the first round by Santiago Ponzinibbio, while Neil Seery hung up his gloves after a submission loss against Alexandre Pantoja.
Chris Weidman snapped a three fight losing streak when he submitted Kelvin Gastelum in the third round.
July ended with the much anticipated rematch between Daniel Cormier and Jon Jones for the light-heavyweight title. The vitriol between the pair continued in the lead-up to the bout before Jones stopped Cormier in the third round. However the result was later overturned to a no-contest after Jones tested positive for steroids.
Tryon Woodley continued his reign as welterweight champion when he beat Damien Maia by decision on the undercard, while Cris Cyborg won the women's featherweight title by stopping Tonya Evinger in the third.
Amanda Nunes beat Valentina Shevchenko to remain the women's bantamweight champion while Rafael Dos Anjos won his second fight in the welterweight division.
Luke Rochold returned to the Octagon after over a year and stopped David Branch in the second round.
Tony Ferguson continued his charge to a lightweight title fight with Conor McGregor by submitting Kevin Lee to give him his tenth consecutive win.
Demetrious Johnson set a new record for title defences when he submitted Ray Borg with an almost unbelievable transition into an armbar to surpass Anderson Silva's record of 10 defences.
Liverpool's Darren Till announced himself to the world with quick stoppage of Donald Cerrone in October, and he also received a performance bonus for his effort.
November saw the return of former welterweight titleholder George Saint-Pierre when he moved up to challenge middleweight champion Michael Bisping. GSP stole the show by submitting the Briton in the third round to become only the fourth person to win a championship title in two divisions.
TJ Dillashaw stops Cody Garbrandt. Picture by: Jason Silva/Zuma Press/PA Images
TJ Dillashaw regained his bantamweight crown when he stopped former teammate Cody Garbrandt in the second round.
Rose Namajunas shocked the world when she dethroned long-time women's strawweight champions Joanna Jedrzejczyk with an impressive first round stoppage while Stephen Thompson put another one in the 'win' column after the outclassed Jorge Masvidal.
Despite signing a new contract, Ireland's Joe Duffy was defeated by James Vick.
Max Holloway confirmed his status as the best featherweight in the world after he stopped Jose Aldo in their rematch in December, while frightening heavyweight Francis Ngannou brutally knocked-out Alistair Overeem to earn himself a title shot in the new year.
Rafael Dos Anjos capped a fine year with a one-sided win over Robbie Lawlor who injured his knee early in the bout while Josh Emmet enjoyed a highlight reel KO, of Ricardo Lamas to finish his year in style.