When Conor McGregor ignited his rivalry with Khabib Nurmagomedov, few could have predicted just how lucrative it would be for both him and the UFC.

Instead of tarnishing his legacy, McGregor and the Russian pulled in huge pay-per-view figures and cemented their positions as global superstars.

Khabib stopped McGregor when they met in 2018 at UFC 229

A whopping 2.4 million people bought the pay-per-view to watch UFC 229 in 2018 and it proved killing people with kindness only paid so much, with bitterness paying the bills instead.

This was never more evident in 2021 when McGregor made his return to the octagon against former foe Dustin Poirier on Fight Island at UFC 257.

The event drew 1.6 million buys to tie it with UFC 202, McGregor's rematch with Nate Diaz, yet defeat and the Irishman's new nice-guy personality threatened to diminish his star power.

Instead, the 33-year-old went on the offensive for the trilogy fight at UFC 264 in July, humiliating Poirier's wife and making serious threats against the Louisiana-native.

The Notorious was left slumped on the Octagon floor at the end of round one

Although McGregor suffered a nasty broken leg at the end of the first round to bring the fight to a close, by replicating his vicious and malicious approach from the Khabib fight in 2018, the Irishman drew more eyeballs to the sport with 1.8 million PPV buys worldwide.

When you compare these numbers to the other UFC numbered events of 2021, it becomes clear just how much of a draw the former two-weight world champion remains.

Of course, official figures for UFC 296 have yet to be released and Poirier may well have again brought huge numbers as a fan favourite, with Amanda Nunes and Sean O'Malley also on the card.

However, 2021 once again belonged to Conor McGregor – the biggest draw in UFC history.