This Saturday night, former WEC welterweight champion Carlos Condit will face off against former Strikeforce welterweight champion Nick Diaz, with the interim UFC welterweight title on the line.
Each of these men has worn championship gold at one point or another, and they'll be looking to wear it once again.
A win on Saturday puts either of these men among the 10 best fighters in the world today, and could possibly earn them a shot at Georges St-Pierre.
Carlos Condit is one of the more overlooked fighters in the division, so here are 10 things you need to know about him heading into UFC 143.
Carlos Condit has been training at Jackson's MMA in Albuquerque, New Mexico for many years, ever since he was 15 years old.
Jackson's is recognized as one of—if not the—best gym in MMA today, and it houses multiple champions of various organizations.
Jackson's has top fighters, top trainers and top talent for the fighters to work with.
In 2006, Carlos Condit was involved in one of the most stacked tournaments in MMA history.
The tournament was run by Rumble on the Rock, and they put together a fantastic field of combatants.
Fighters such as Condit, Jake Shields, Yushin Okami, Anderson Silva and Frank Trigg were involved.
Condit made it to the finals of the tournament where he lost a unanimous decision to Jake Shields.
At this point, Condit was just 15-2 and only 22 years old. He sure has come a long way.
Condit may not have beaten Shields, but that doesn't mean he doesn't have a lot of impressive names on his resume.
If you look at his wins, Condit holds the chin of Dan Hardy on his mantle, as he was the first man to knock him out.
Condit took away the perfect records of Rory MacDonald and Dong Hyun Kim, as he knocked both of them out.
Condit also has a submission victory over Frank Trigg and a decision victory over Jake Ellenberger.
He's got quite the list of victims.
Carlos Condit is a purple belt in Brazilian Jiu-Jitsu. The purple belt is the middle belt in jiu-jitsu ranking systems. It follows blue and white, and precedes brown and black.
Condit may only be a purple belt, but that hasn't stopped him from racking up quite a number of submission victories throughout his career.
His nickname is "The Natural Born Killer" and it is one of the most fitting nicknames in MMA today.
Condit has a killer instinct that isn't seen in every fighter out there, and it isn't something that can be taught.
In 27 victories, Condit has finished 26 of his opponents, the only one making it to a decision being fellow top-10 welterweight, Jake Ellenberger.
Even if you see someone with that many finishes, you don't often see someone who is well rounded enough to knock out and submit his opponents.
Carlos Condit was the former, and final, WEC welterweight champion.
Condit won the belt at WEC 26, where he submitted John Alessio with an armbar in the second round. He then defended the title three times, scoring two submission victories and a TKO.
After his final defense at WEC 35, the welterweight division was dissolved into the UFC and Condit made his UFC debut.
After his perfect 5-0 run in the WEC, Condit dropped his first fight in the UFC, when he lost a split-decision victory to Martin Kampmann.
Since that loss, Condit has gone 4-0 with three finishes, including wins over Jake Ellenberger by decision, Rory MacDonald via TKO, Dan Hardy via KO and Dong Hyun Kim via KO.
With that impressive run, Condit put himself into this current title scrum.
The current title picture has been confusing to say the least.
Originally, UFC 137 was going to feature a fight between Georges St-Pierre and Nick Diaz, and another fight between Carlos Condit and B.J. Penn.
Then it became Georges St-Pierre vs. Carlos Condit and Nick Diaz vs. B.J. Penn.
Then GSP-Condit didn't happen, and Condit was rescheduled to fight Josh Koscheck at UFC 143.
Then when GSP got injured again, it became Condit vs. Nick Diaz for the interim title.
This has been a confusing few months for Condit and the entire welterweight division.
In just five fights in the UFC, Condit has earned three Fight Night bonuses.
He has two Knockout of the Nights, and one Fight of the Night.
His first award came against Rory MacDonald at UFC 115, where he earned a TKO with seven seconds left in the fight, and he took home the Fight of the Night award.
Then at UFC 120, he earned his first Knockout of the Night for the brutal left hook that put Dan Hardy to sleep.
He followed that up at UFC 132, where he earned Knockout of the Night once again for the flying knee that put Dong Hyun Kim out cold.
What could be next for him?
On Saturday night, you can find out what's next for Carlos Condit, as he will face off with Nick Diaz in the main event of UFC 143 with the interim welterweight title on the line.
Does Condit have another Knockout of the Night in him? Or will him and Diaz have a war and earn a Fight of the Night?
Tune in to the PPV on Saturday night and we'll see what's next for "The Natural Born Killer."