Jacob Fatu raised the stakes in his feud with Roman Reigns by challenging the World Heavyweight Champion to Tribal Combat.

May 19 (UPI) -- Jacob Fatu raised the stakes in his feud with Roman Reigns by challenging the World Heavyweight Champion to Tribal Combat.

Fatu, on Monday, immediately called out Reigns to meet him in the ring at the start of Raw.

Reigns arrived to the arena where he was greeted by general manager Adam Pearce who stated he was going to fire Fatu for attacking WWE officials in recent weeks. Reigns said he needed to handle business first and started heading towards the ring.

Jimmy and Jey Uso reached Fatu first inside the ring. Jimmy Uso attempted to plead with his cousin but when words didn't work, Jey Uso attacked Fatu with a steel chair.

Fatu was able to overwhelm The Usos when Reigns finally arrived onto the scene. After an intense brawl, Reigns and The Usos gained the advantage.

Reigns nailed Fatu with a Superman Punch after he was tied up in the ropes. The Usos also hit Fatu with a flurry of their special moves and ended the beat down when Reigns delivered a Spear.

It was then that Pearce walked to the entrance ramp and prepared to fire Fatu. As Pearce started to speak, Fatu interrupted and screamed "Tribal Combat!"

The Usos and Pearce tried to talk Roman out of accepting the match, but the champion agreed. Reigns will defend his World Heavyweight Championship against Fatu at Clash in Italy on May 31.

A Tribal Combat match has no rules. The loser must bow and acknowledge the winner as the Tribal Chief.

Also on Raw, Oba Femi continued his open challenge when he was suddenly and shockingly attacked from behind by his foe Brock Lesnar.

Lesnar hit Femi with a number of F5's that left the towering competitor decimated.

Femi had defeated Lesnar at WrestleMania 42 in April. Lesnar, after having lost the match, appeared to retire after he left his boots and gloves in the middle of the ring. WWE had also moved Lesnar to their alumni section but at least for now, The Beast is back.