UFC 239 is in the history books and we got a night of stunning action from Las Vegas.
Jon Jones kept his undefeated MMA record intact by successfully defending his light heavyweight championship against Thiago Santos - but lost on one scorecard for the first time in his career.
Amanda Nunes also defended her bantamweight title in stunning fashion, knocking out Holly Holm in one round with a head kick to remain a two-weight champion.
And perhaps the biggest talking point of the night was Jorge Masvidal's KO of Ben Askren.
It took only five seconds for 'Gamebred' to finish the fight with a running knee, bringing the former ONE Champion firmly back down to earth.
- Masvidal records fastest KO in UFC history against Askren
- Steve-O challenges Bieber to exhibition MMA fight
- Ngannou stops JDS in just 71 seconds at UFC Minneapolis
But the most exciting action until Masvidal's flash knock-out came outside of the Octagon.
Not long before the main card of the event started, footage began to circulate on social media of two top-name fighters seemingly involved in an altercation at cageside.
As Khabib Nurmagomedov and his entourage were getting ready to watch the action, Nate Diaz walked behind Team Khabib and exchanged words with the lightweight champion of the world.
Just as it looked like Diaz was walking away, the Russian and members of his team suddenly stood up and it looked like a fight may break out.
But security swarmed in to stop anything physical from happening - you can check it out below.
Respected ESPN journalist Brett Okamoto played down the incident, quoting Khabib's manager Ali Abdelaziz in saying that 'Nate directed some words at Khabib's camp and was quickly removed'.
It's never going to be quiet when Nate Diaz is around, and he's managed to make a lot of noise for such a short altercation.
Both Khabib and Diaz have fights coming up - Nurmagomedov will try to unify the lightweight division against Dustin Poirier in Abu Dhabi in September, and Diaz will face Anthony Pettis at UFC 241 next month.
That will be at welterweight, but if Diaz wants the Russian inside the Octagon, he may have to drop to the weight class that Khabib holds all the cards in for a shot at the undefeated Dagestani - despite not fighting in the 155 division since 2015.