UFC fighter Nate Diaz lights marijuana joint live on national television

The UFC's production crew got much more than they bargained for when they cut to a shot of fighter Nate Diaz sitting cageside at the UFC Fight Night in Austin, Texas on Monday (NZT).

Expecting little more than the obligatory display of the fist and steely stare, they were instead subjected to the notoriously surly Diaz producing a marijuana joint and lighting it up, all while live on national TV.

The incident arguably stole the show on the evening, producing a cheer to rival that of hometown hero Derrick Lewis upon his knock-out finish of Russian Marcin Tybura.

Personal use of marijuana, while legal in a number of states including Colorado and California, is still considered a criminal offence in Texas.

There's no official word yet on any repercussions for Diaz, whose staunchly unyielding style has earned him cult status among fans.

The Stockton, California native is the only fighter to ever defeat Irish superstar Conor McGregor in the UFC, with the two supposedly in talks for a decisive third contest after splitting honours one apiece through their first two bouts.