UFC has been left reeling from Khabib Nurmagomedov's shock retirement on Saturday evening at UFC 254.
Forcing Justin Gaethje to tap out in just the second round of their lightweight unification bout this past weekend in Abu Dhabi, few had foreseen the 29-fight undefeated champion hanging up his gloves.
His absence is set to leave a seismic void on the UFC landscape, but it has also drawn many to look back on many of his ferocious wins, not least his most infamous one over Conor McGregor.
As the two met in Las Vegas back in 2018, MMA pay-per-view records were smashed, with an estimated 2.4 million having purchased the fight at the T-Mobile Arena.
Having won the lightweight crown against Al Iaquinta in New York earlier that year, Nurmagomedov made his first title defence against the former champion, to a frenzied media circus.
Both men had lost little love for one another before the fight, and the bout itself will live in the memory for many a year.
With the fight having gone 15 minutes, the fourth round saw McGregor come under increasing pressure from Khabib's relentless attacks.
As the round ticked into its fourth minute, the Irishman - locked in a neck crank submission hold - then screamed the words few had expected to hear:, 'Let me go, please' - as Khabib himself claimed.
Given McGregor's tough-talking reputation, the reported nature of his defeat was eye-opening.
Khabib's following actions in scaling the Octagon cage then shocked a global audience.
Leaping from the ring to attack McGregor's former teammate Dillon Danis, UFC officials and security were left scrambling.
A rematch was mooted for some time after, but never transpired.
In his 29 fights undefeated, Khabib has now gone down as the number one fighter in the history of the lightweight division.
Against McGregor, his win was reminder of just how dominant a fighter Khabib Nurmagomedov was.