The worst keep secret in combat sports has been confirmed, with the UFC announcing Conor McGregor will meet lightweight champion Rafael Dos Anjos at UFC 197.
MORE: Stars who could save WrestleMania 32 | Best fighters of 2015
Las Vegas's MGM Grand will host the March 6 (AEDT) pay-per-view event, which will also feature a blockbuster women's batamweight title fight between Holly Holm and Miesha Tate.
McGregor will move up from featherweight to challenge Dos Anjos, while Holm makes her first defence of the UFC crown she won after beating Ronda Rousey in Melbourne last November.
The Dos Anjos fight is part of an ambitious plan by McGregor, above, to be a dual-weight world champion - a feat not yet achieved by any fighter in the UFC.
The card is the biggest in UFC history, and fans wanting to book their place in Las Vegas will have to be quick.
Tickets for the event go on sale January 22, with UFC 197 expected to land the organisation a gate record.