The brief yet rich history of Submission Underground is filled with forces from the world of combat sports colliding in epic and unforgettable fashion.

The submission only showcase draws mixed martial artists and jiu-jitsu aces alike to the yellow cage inside The Roseland Theater, and despite just four events under the promotional belt, the Chael Sonnen led operation has already created some of the most memorable grappling highlights of the past year.

From Jon Jones hitting a lightning-quick super duck on former Olympian Dan Henderson to UFC light heavyweight Antonio "Shoeface" Carlos Jr. locking Danaher Death Squad member Garry Tonon in the grips of a flying triangle, the action at SUG has stormed fast and ferocious onto the scenic shores of Portland.

This Sunday night the next chapter will be added.

Several high profile bouts line the main card for the fifth installment of the upstart grappling showcase, and the men and women on the docket will be looking to carve out the next great moment in SUG history. The action streams live and exclusive on FloGrappling and kicks off on Sunday afternoon at 2:00 pm PDT

Let's take a quick look at the bouts that make SUG 5 a can't miss event.

Sarah Kaufman vs Amanda Diggins

Any time you match a former world champion fighter in with an up-and-coming talent the stage is set for drama of the highest order. The former Strikeforce champion turned UFC veteran has been one of the biggest names in women's MMA for the better part of the past decade, and has notched fights against some of the biggest name her sport has ever seen.

That said, Kaufman has hit rough waters inside the cage as of late, and is currently standing at a crossroads in her competitive career. The British Columbia native knows she still has the fire to compete, but being without a UFC contract at the current time has created opportunity where none seemed to exist previously.

Kaufman jumped at the chance to face Diggins because she wants to get back into the winner's circle before making a strong push back into her MMA career, and that's exactly what the Oregon native is looking to prevent.

Diggins has no intention of allowing Kaufman to come into her sport and plant her flag and plans to defend her figurative and literal home turf with ferocity. The surging grappler knows Kaufman has the bigger name in this equation, but also understands how knocking off a known commodity can boost her own trajectory.

AJ Agazarm vs Phil Baroni

The world of combat sports is filled with characters, but few enjoy the type of notoriety Phil Baroni and AJ Agazarm bring to their respective realms.

The Florida-based grappler is easily one of the most disliked players on the jiu-jitsu landscape, and it's a status earned through hot-fire trash talk and arrogance. Agazarm simply loves to get people riled up, and when the target falls squarely on the man standing across from him, things have a tendency to push to the brink of chaos.

Agazarm can travel this avenue because he has more than enough chops to back up his chatter, and a recent silver medal winning turn at the renown ADCC tournament last week will only serve to bolster an already raging sense of self-confidence.

Yet, when it comes to self-belief and letting the machismo flag fly, no one has done it with the flair and zest of Phil Baroni.

"The New York Badass" emerged as a colorful personality in a young sport during the early days of MMA. Just think about that...in a sport filled with outlaws and renegades Baroni stood out for his willingness to take things back to the streets and away from the tenants of martial arts that are so highly coveted by those who practice the discipline.

Baroni simply loves the ruckus and has no time for all the bowing and pajama wearing that comes from traditional martial arts. Throw an ever-combustible Agazarm into the cage with Baroni and both chaos and entertainment are guaranteed.

Andrew Alexander vs Joe Baize

Leglocks are the jiu-jitsu equivalent to throwing the knuckleball in baseball. Every competitor worth their salt can execute them but it takes a specialist to really bring out the nuances that make the move effective.

Both Andrew Alexander and Joe Baize are firmly in the leg game.

The 10th Planet representative most likely takes his morning coffee in 50/50 while Baize has built his name through his aggressive attacks. Either way it plays out there will be four legs inside the SUG cage for this match on Sunday afternoon and zero of them are safe.

Craig Jones vs Ben Egli

On a card lined with recognizable names, Craig Jones will show up to Portland with more than a little momentum at his back.

Not only did Jones make the trip to Finland and outperform the expectations many placed on him heading into ADCC, but did so by submitting grappling monster Leandro Lo. Jones toppled Lo to cement one of the biggest upsets of the entire tournament, and that accomplishment has upped the wattage of the spotlight he'll find at SUG 5.

And if ADCC serves as proof of what Jones can do when the pressure is on then Portland should be in for a show on Sunday.