The historic fight tops the bill at the Garden despite no title on the line – or at least that was the case initially.
The BMF belt will be handed to the victor tonight, which seemingly means as much as anything to these two men.
In an action-packed fight, there is also the lingering prospect of Conor McGregor fighting the winner.
Here’s everything you need to know about the fight.
When is the fight?
The fight is on November 2 in New York at Madison Square Garden.
UFC 244 will kick off at 8pm ET (midnight GMT) with the preliminaries and the main card expected at 10pm ET (2am GMT).
The main event will therefore not start until closer to midnight ET (4am GMT).
How can I watch it?
You can watch the fight in the UK on BT Sport 1 with a live stream available here from all mobile devices, coverage starts at midnight GMT.
You can catch the fight on the BT Sport app on Xbox, PS4, Apple TV and Samsung Smart TVs.
If you are not a BT customer but are an EE customer, you can sign up for a free trial and watch the fights at no cost. Click here to sign up
UFC 244: Masvidal v Diaz – Main card
Welterweight: Jorge Masvidal v Nate Diaz
Middleweight: Kelvin Gastelum v Darren Till
Welterweight: Stephen Thompson v Vicente Luque
Heavyweight: Derrick Lewis v Blagoy Ivanov
Lightweight: Kevin Lee v Gregor Gillespie
UFC 244: Masvidal v Diaz – Preliminary card
Light Heavyweight: Corey Anderson v Johnny Walker
Featherweight: Shane Burgos v Makwan Amirkhani
Middleweight: Brad Tavares v Edmen Shahbazyan
Heavyweight: Andrei Arlovksi v Jairzinho Rozenstruik
Dan White, UFC president: “This fight is a big deal for the division, for who’s next in the title picture and obviously it’s a huge fan favourite fight .
“This thing took on a life of its own, it’s a big fight and it’s not only a fight that people want to see, it’s an important fight in the division, in the title picture.”
Conor McGregor: “I think Diaz beats him. He’s got crisper boxing, way more experience. I think Masvidal’s had a good run, he’s had a two fight win streak.
“The game is very forgetful I believe, our sport is, I think Diaz has enough in him to do it.
“I think he’s in a better space. You’ve got to factor that in, what kind of space is the fighter in because everyone’s the best on their day. I think Diaz beats him.”