Jon Jones: 5 Career-Defining Moments Ahead of UFC 140 Fight Card

Jon Jones has only been in the sport of mixed martial arts for four years now. However, in those four years, Jones has become one of the top 10 fighters in the sport today, and has already left a big mark on MMA fans.

In those four years, he has had 15 fights and has a professional record of 14-1, with the lone loss being a disqualification.

With Jones set to make his second title defense on Saturday, let's take a look at the five defining moments of his career.

No. 5: MMA Debut Against Brad Bernard

Jones' first fight took place on April 12, 2008, and it was against Brad Bernard.

In just 1:32, Jones had defeated Bernard via TKO.

This was the beginning of a great career.

Jones would go on to rattle off six straight victories, five (T)KOs and one submission, on the way to his...

No. 4: UFC Debut vs. Andre Gusmao at UFC 87

In Jones' UFC debut, he faced off against Andre Gusmao, who was also making his UFC debut.

Both fighters came into the fight undefeated, but it would be Jones who left with his record intact, as he beat Gusmao handily, earning a 30-27 unanimous decision on all judges' scorecards.

Gusmao had one more fight in the UFC before being cut, but Jones would go on to do great things.

No. 3: Defeating Ryan Bader at UFC 126

At UFC 126, it was the battle for the future of the light heavyweight division, as Jon Jones, then 11-1 going into the fight, fought Ryan Bader, who was 12-0.

In typical Jones fashion, he was not in trouble once during the bout, and was able to submit Ryan Bader in the second round with a guillotine choke.

However, it was what happened after the bout that many will remember, as that is when Jones was offered a title shot.

No. 2: First Light Heavyweight Title Defense Against Rampage Jackson at UFC 135

In the first defense of his light heavyweight title, Jon Jones was scheduled to face Quinton "Rampage" Jackson.

Rampage was coming into the fight on a two-fight win streak, with victories over Matt Hamill and Lyoto Machida.

In typical Jones fashion, he was never in trouble for a second, as he was able to submit Rampage with a rear-naked choke in the fourth round and he became the only person to finish Rampage inside the Octagon.

No. 1: Defeating Mauricio Rua for the Light Heavyweight Title at UFC 128

There's no doubt what No. 1 is. When Jon Jones became the light heavyweight champion, he lived up to all the hype and became the youngest champion in UFC history.

Jones' career will forever be defined by his win over Shogun Rua, as he became the only many to truly dominate Shogun, and also became the only person to stop him with strikes.

On Saturday, he'll look to become the first person to defend his light heavyweight title more than once in nearly five years.

Tim McTiernan is a Featured Columnist for Bleacher Report. For the latest news on everything MMA, follow me on Twitter @tmt2393.