Brazilian heavyweights Junior "Cigano" Dos Santos (10-1) and Gabriel "Napao" Gonzaga (11-4) have officially been re-booked to square off in the co-main event of the first-ever UFC on Versus event, which is scheduled for the Odeum Colorado in Broomfield, Colo., on March 21.

The two were originally set to tangle at UFC 108 on Jan. 2; however, "Napao"  was forced to withdraw from the fight about five weeks out because of a severe staph infection.

Pride FC veteran, Gilbert Yvel, filled in on short notice for Gonzaga and wound up on the wrong end of Dos Santos' third first round technical knockout inside the Octagon.

Before that, "Cigano" had cemented his place among the heavyweight big guns when he had former Pride FC star Mirko "Cro Cop" Filipovic pleading for "No Mas!" after a three-round drubbing at UFC 103. The hard-hitting monster is likely right on the cusp of his first opportunity to fight for a world title.

And a win over the promotion's former number one contender may just push him over the top.

Gonzaga, on the other hand, warmly welcomed Chris Tuchscherer to the promotion with a devastating first round ball bash at UFC 102 back in August. The Minnesota Martial Arts Academy-trained fighter was given time to recover; however, he returned to get utterly smashed shortly thereafter by a relentless "Napao."

It marked the third win in four attempts for Gonzaga. But the former number one contender has struggled against top competition. He'll try to shuck that label once again when he squares off against his fellow countryman on fight night.

UFC on Versus 1 is set to feature a ridiculous main event between dynamic light heavyweight strikers Brandon "The Truth" Vera and Jon "Bones" Jones. Anthony "Rumble" Johnson, Clay "The Carpenter" Guida, John "Doomsday" Howard, Sean "The Muscle Shark" Sherk, Spencer "The King" Fisher and others are also expected to be in action on what is shaping up to be a great card for the promotion's debut on the Versus network.

To check out the latest fight card and rumors for UFC on Versus 1: "Vera vs. Jones" click here.