It's an unfortunate reality of combat sports that too many fighters don't know when to step away from the limelight.

Whether it's the result of the intoxicating thrills of being on top of the world, or years of bad financial decisions, the history books are littered with competitors who overstayed their welcome.

Fighters who leave during their primes are sadly the exception, rather than the rule.

Not only has Georges (Rush) St. Pierre made the sensible decision to take an indefinite leave of absence from mixed martial arts, he's set an example other professional athletes can learn from, even if he may one day return to the cage.

If a fighter can't retain the laser focus necessary to compete at a high level, there's no shame in calling it quits.

St. Pierre is arguably the biggest star MMA has ever produced. Yet, none of the money, the fame, nor the controversy from his last fight can deter him from fixing his personal life -- and rightly so.

During a media call Friday, St. Pierre refused to go into further detail regarding the issues that keep him up at night, but admitted the stress of being champion had become too much to bear. He also shot down the notion that he's walking away due to health concerns.

“There's a lot of pressure,” St. Pierre began. “Every fight, I'm carrying weight on my shoulders. With every fight, you add more weight on your shoulders. At one point, it becomes so heavy that I have a hard time carrying it myself. Physically, I'm 100% -- I'm still young and on top of the world -- but mentally, I just feel I can't go through another training camp right now and I don't know when I will be able to.

“I've decided I need to take time off. I know the UFC is a business and they can't wait for my little personal (problems). They have to keep things rolling. So I've vacated my title out of respect to the other competitors. One day, when I feel like it, I might come back. But right now, I need a break.”

As classy as St. Pierre's announcement is, it's not exactly shocking.

The Tristar welterweight made similar remarks immediately following his ninth consecutive title defence, a debatable split-decision win against Johny Hendricks at UFC 167 last month. If anything, the news may be disappointing to fans who were clamouring for an immediate rematch.

At the post-fight press conference, UFC president Dana White was critical of St. Pierre's decision. However, he now feels the Montreal fighter has made the right move.

“I agree with him 100%,” White said on the call. “This is fighting. You have to be 100% mentally, physically and emotionally (invested). If not, you should sit out and wait until you get your stuff cleared up. I think it's the right move.”

St. Pierre's decision to vacate the title comes roughly two weeks away from the six-year anniversary of his current championship stint. He's left behind a legendary run in the welterweight division that will be tough to top.

He originally claimed the 170-pound strap with a TKO win over Matt Hughes on Nov. 18, 2006, but quickly lost the championship via TKO to Matt Serra less than five months later. He then captured the interim title with a submission win over Hughes on Dec. 29, 2007, before securing a TKO victory over Serra to unify the belts four months later.

St. Pierre went on to defend the championship nine times, setting a new record for the welterweight division. He also established benchmarks for victories under the UFC banner at 19 and wins in UFC title fights at 12.

However, former middleweight kingpin Anderson Silva still owns the most consecutive UFC title defences with 10.

During his lengthy championship reign, St. Pierre earned victories over B.J. Penn, Jon Fitch, Josh Koscheck and Jake Shields, before being sidelined for a year due to a torn ACL. Despite this lengthy hiatus, he reclaimed his throne in late 2012, netting wins over Carlos Condit, Nick Diaz and Hendricks.

Though St. Pierre said he plans to return to the cage one day, he admitted he could retire tomorrow without regret.

“I'm content,” St. Pierre said. “There were a lot of things I wanted to do. I wanted to be the greatest. I also said before that I wanted to do things to be remembered. I wanted to do things to be remembered, make a difference in the sport and make the sport reach a different level.”

Regardless of whether or not fans get the privilege of watching him fight again, St. Pierre has left on mark on MMA that won't soon be forgotten.

HENDRICKS VS. LAWLER

On the heels Georges (Rush) St. Pierre's decision to vacate the welterweight title, UFC brass will waste no time crowning a new champion.

During a media call Friday, UFC president Dana White announced Johny (Bigg Rigg) Hendricks will battle Robbie (Ruthless) Lawler to crown a new 170-pound kingpin in the co-main event of UFC 171 in Dallas March 15.

“There's no doubt the Robbie Lawler and Johny Hendricks fight will be an absolute gunfight,” White said.

Currently ranked No. 1 at welterweight, Hendricks lost a controversial split decision to St. Pierre at UFC 167 last month. That same night, Lawler won a thrilling split decision over Rory MacDonald to secure the No. 3 spot.

GSP'S TOP FIGHTS

Whether or not the proud Canadian ever returns to fighting, he has cemented his spot as the greatest welterweight in MMA history.

Here's a list of the most important fights of his career.

5. FITCH

After an ill-fated maiden voyage as welterweight champ, St. Pierre's thrashing of Jon Fitch at UFC 87 in 2008 marked his first successful title defence.

The fight sent a message to the 170-pound division; the newly-crowned kingpin wasn't leaving any time soon.

4. CONDIT

Following a lengthy hiatus due to ACL surgery, fans wondered if St. Pierre would still be able to perform at his usual high level.

He erased all doubts with a thrilling unanimous-decision win over Carlos Condit at UFC 154 late last year.

3. PENN

B.J. Penn's close split-decision loss to St. Pierre at UFC 58 in early 2006 no doubt ate away at the Hawaiian, who later talked his way into a rematch at UFC 94 in early 2009.

Penn probably should have kept him mouth shut, as St. Pierre responded by brutalizing the then-lightweight champ en route to a late TKO win.

2. SERRA

St. Pierre's shocking TKO loss to Matt Serra in 2006 played a pivotal role in shaping him into the champion he would later become.

Not only did it light a fire under him, it taught him never to underestimate an opponent.

The defeat may have been bitter, but St. Pierre's revenge was one of the sweetest wins of his career. He destroyed Serra in front of a rabid Montreal crowd at UFC 83 in 2008.

1. HUGHES

When St. Pierre first fought Matt Hughes at UFC 50 in 2004, he was too awestruck to even look the MMA legend in the eyes.

Fast forward two years and the Tristar fighter was cracking his shin across Hughes' head to capture his first welterweight title. He then conquered the trilogy with a submission win at UFC 79 in late 2007.