It started with some barbs, then escalated to a (questionably binding) contract on Twitter, and now the fight between Daniel Cormier and Roy Nelson is a reality. The two heavyweights have verbally agreed to a showdown in the co-main event of UFC 166 in Houston.

The announcement confirms that fan favorite Nelson has struck a deal with the organization and will continue to fight in the Octagon -- a subject of much speculation following his UFC 161 loss on the last fight of his previous contract.

In the main event of UFC® 166, the fate of the world heavyweight championship will be decided when the two baddest men on the planet – UFC heavyweight champion Cain Velasquez (a teammate and friend of Cormier) and rival former heavyweight champ Junior dos Santos – collide for the third time in their blistering series.

Tickets for the event, set to take place Saturday, October 19, at the Toyota Center, go on sale Friday, August 2.