Bellator MMA Featherweight World Champion Patricio Pitbull (23-2), the hard-hitting Brazilian who believes he’s the best 145-pounder on the planet, returns to action on Friday, June 19, when he puts his belt on the line against dynamic contender and five-time Bellator MMA veteran Georgi “Insane” Karakhanyan (24-4-1).

Patricio Pitbull vs Georgi Karakhanyan co-main event at Bellator 138

The championship bout serves as the co-main event of “Bellator MMA: Unfinished Business.”

Featuring one of the most anticipated fights in the history of the sport with Kimbo Slice vs. Ken Shamrock, “Bellator MMA: Unfinished Business” takes place Friday, June 19, at St. Louis’ Scottrade Center and airs live on Spike TV.

Tickets for “Bellator MMA: Unfinished Business,” which start at just $30, are currently on sale at Ticketmaster.com

Additional contests will be announced shortly.

Pitbull vs. Karakhanyan is a rematch more than four years in the making, as the current champion downed the challenger via third-round TKO in the Bellator cage in March 2011. However, Karakhanyan – who was born in Russia but now lives in Riverside, Calif. – has gone 10-1 in his 11 appearances since, picking up a pair of championship belts in smaller promotions while earning his way back to a Bellator MMA title fight.

“Insane” returned to the Bellator MMA cage in January, shocking top up-and-comer Bubba Jenkins with a dominating first-round submission win.

“June 19 brings an opportunity for me to avenge an old loss in this rematch with Pitbull,” said Karakhanyan. “People are going to see an all-out war, and when it is all said and done the belt is going to look great around my waist.”

The 27-year-old Pitbull, of Natal, Brazil, is a 13-time veteran of the promotion who captured the Bellator MMA Featherweight World Title with a September win over then-champion Pat Curran. Pitbull then defended his belt in January with a thrilling submission win over former champion Daniel Straus.

“Karakhanyan is a fighter among the top of the weightclass,” said Pitbull, “but I’m one dimension above. If you see a fight where I’m not hit from a single attack don’t be surprised. I’m preparing to not being hit and I guarantee to show absolute superiority in this new challenge!”

In 24 career appearances, Pitbull has only lost two fights, and both were the result of razor-thin, split-decision results.

“Bellator MMA: Unfinished Business” – Friday, May June 19, Scottrade Center, St. Louis, Mo.

Bellator Heavyweight Main Event: Kimbo Slice (4-2) vs. Ken Shamrock (28-15-2)
Bellator Featherweight Title Fight: Champ Patricio Pitbull (23-2) vs. Georgi Karakhanyan (24-4-1)
Bellator Featured Lightweight Fight: Michael Chandler (12-3) vs. Derek Campos (15-4)