The Career-Defining Moment of Each Welterweight Champion in UFC History

Georges St-Pierre and Matt Hughes have positioned themselves as the most dominant welterweights to ever compete inside the Octagon. They are currently tied for the most title fights in UFC history with 12. 

However, interspersed between and around each of their title reigns, there were four other welterweights who had the honor of feeling the heft of UFC gold around their waists.

Some of these fighters have had more of an impact on the welterweight division than others, but they have all served to add something to the 170-pound landscape.

This is a list of moments that have defined each of these welterweight champs. These are the moments that will remain indelibly seared in the minds of all MMA fans.

Pat Miletich (29-7-2)

Reign: Oct. 16, 1998 - May 4, 2001 (931 days)

Pat Miletich defeated Mikey Burnett via a somewhat controversial split decision to win the inaugural welterweight title at UFC Ultimate Brazil (aka UFC 17.5).

Miletich successfully defended the strap four times before losing it to Carlos Newton. 

Defining moment: Miletich had a long and successful fighting career that spanned 13 years, but his win over Burnett stands as his biggest accomplishment in the cage. The victory ensures Miletich's place in UFC history as the promotion's first welterweight titleholder.

However, Miletich received a greater level of notoriety after founding Miletich Fighting Systems (MFS) in 1997.

The camp is widely regarded as one of the best in mixed martial arts. It has been the training grounds for 11 different titleholders including Tim Sylvia, Robbie Lawler, Jens Pulver and Matt Hughes.

Carlos Newton (16-14)

Reign: May 4, 2001 - Nov. 2, 2001 (183 days)

Carlos Newton wrested the belt from Pat Miletich at UFC 31: Locked and Loaded. He defeated Miletich via submission (bulldog choke) in the third round.

In his first title defense, Newton had the misfortune of being matched against Matt Hughes, one of Miletich Fighting Systems' best.

Defining moment: This victory over Miletich stands as the brightest moment of Newton's career.

"The Ronin" has been involved in a number of wars with the likes of Anderson Silva and Dan Henderson, but he regularly found himself on the losing side of things.

However, unfortunately, most MMA fans will remember Newton for his first fight with Hughes. Newton made a flamboyant WWE-style entrance. He wore an afro wig, a sparkly get-up and was flanked by beautiful women.

In the bout, Newton caught Hughes with a tight triangle choke that almost put him to sleep. With the last bit of his energy, Hughes lifted Newton up and then slammed him down to the canvas. The blow knocked the champ out cold.

Eight months later, Newton received another crack at Hughes, but the end result was no different than their first go-around. Hughes won via TKO in the fourth round.

Newton's last official MMA fight was a unanimous-decision loss to Brian Ebersole at Impact FC 1 in 2010. He now focuses his attention on coaching at his home gym, Warrior Mixed Martial Arts.

Matt Hughes (45-9)

Reign No. 1: Nov. 2, 2001 - Jan. 31, 2004 (820 days)

At UFC 34: High Voltage, Matt Hughes blasted Carlos Newton with a powerbomb slam that rendered the champ unconscious. More than a decade later, the devastating knockout lives on in highlight reels.

Defining moment: Hughes' whole career is chock full of defining moments, but one that fans will always remember is his first fight with Frank Trigg at UFC 45.

Their rivalry was legendary. Hughes and Trigg flat out hated each other. Their fight was a grappling war that ended with Hughes securing a standing rear-naked choke in the first round.

Reign No. 2: Oct. 22, 2004 - Nov. 18, 2006 (757 days)

Matt Hughes recaptured the vacant welterweight title at UFC 50 by defeating Georges St-Pierre via armbar submission. The loss marked the first of GSP's career.

Defining moment: His second scrap with Trigg is just as memorable as their first go-around, but Hughes' best moment has to be his catchweight fight with Royce Gracie at UFC 60.

Gracie represented the old school of MMA. He was the one who brought Brazilian jiu-jitsu to the masses.

Hughes caught Gracie early in an armlock, but not surprisingly, he couldn't get him to tap. Hughes let the submission go, improved his position and proceeded to land unanswered shots that forced the ref to stop the fight at 4:39 of the first round.

The event became the best-selling UFC pay-per-view up to that time, pulling in over 600,000 buys. 

Hughes retired from MMA in January 2013. He was recently inducted into the UFC Hall of Fame and was named the vice president of athlete development and government relations.

B.J. Penn (16-9)

Reign: Jan. 31, 2004 - May 17, 2004 (107 days)

B.J. Penn defeated Matt Hughes via submission (rear-naked choke) at UFC 46: Supernatural, snatching the belt from arguably one of the greatest welterweights of all time.

In 2004, Penn was stripped of the title when he left the UFC to compete under the K-1 banner; however, this would not be the last time fans would see "the Prodigy" fight inside the Octagon.

Defining moment: Penn is one of a handful of fighters that have truly left an indelible imprint on two different UFC weight classes. 

After making his return to the UFC, Penn went on to defeat Joe Stevenson to win the vacant lightweight strap. This victory made Penn one of only two men in UFC history to win championship belts in two different weight classes.  

"The Prodigy" has been involved in a number of amazing fights. Each one of them has added to his legacy, but the moment that defines Penn's career actually came in a bout he lost. 

While still fighting with K-1, Penn took on future UFC light heavyweight champ Lyoto Machida in an openweight bout. It was an obvious size mismatch, though this didn't keep Penn from giving "the Dragon" all he could handle during their three-round affair.

Penn lost via a unanimous decision, but this fight served to underline his "I'll fight anyone" attitude that endeared him to MMA fans throughout his career.

Matt Serra (18-7)

Reign: Apr. 7, 2007 - Apr. 19, 2008 (378 days)

In what is hands down the biggest upset in UFC history, Matt Serra shocked the world by defeating Georges St-Pierre via a brutal TKO in the first round of UFC 69.

Defining moment: Obviously, this win over the greatest welterweight of all time is the definitive moment in Serra's career. In 2006, Serra was a part of the cast of The Ultimate Fighter: The Comeback. He won the show and received a guaranteed title shot.   

Serra entered into the fight as a huge underdog. He was a living, breathing Rocky Balboa and the embodiment of what is truly great about sports. His finish of St-Pierre was something so unreal that it would have seemed far-fetched in a Hollywood melodrama.

The victory earned Serra Knockout of the Night honors. He also stands as one of only two fighters to ever beat GSP.

On May 22, 2013, Serra announced his retirement from MMA. He did leave the door open for a return if the UFC ever holds a card at Madison Square Garden.

Georges St-Pierre (24-2)

Reign No. 1: Nov. 18, 2006 - Apr. 7, 2007 (140 days)

At UFC 65: Bad Intentions, St-Pierre ran through Matt Hughes, finishing him with some vicious strikes in the second round. This was a big win for GSP because, at the time, Hughes was not only the welterweight champ but also widely regarded as one of the pound-for-pound greatest fighters.

Defining moment: St-Pierre's loss to underdog Matt Serra at UFC 69 really served to define his career moving forward. The defeat chipped away at his perceived invincibility and forced him to go back to the drawing board when it came to his fighting strategy.

Some may argue that St-Pierre fights far too conservatively now. He is cautious, relying on superior takedowns and ground strikes to neutralize his opponents. This strategy is quite effective, but it can result in "boring" fights.

Reign No. 2: Apr. 19, 2008 (Incumbent)

Georges St-Pierre exorcised some demons and reclaimed the welterweight belt at UFC 83 by defeating Matt Serra via TKO (knees to the body) in the second round.  

Defining moment: Since beating Serra, GSP has gone on an eight-fight win streak. The most impressive of those wins came against former welterweight champ B.J. Penn at UFC 94.

Penn has the heart of a warrior and is notoriously hard to finish. St-Pierre worked him over with vicious ground-and-pound. GSP broke Penn's will, leaving him beat-up and bruised. Not wanting to see Penn take any more punishment, his corner decided to throw in the proverbial towel.

Now, while it seems unlikely that a superfight with middleweight kingpin Anderson Silva will ever happen, St-Pierre still has a compelling matchup with the hard-hitting Johny Hendricks looming on the horizon.