When a still-green Junior dos Santos made his UFC debut, few picked him to upset veteran heavyweight Fabricio Werdum in such stunning fashion in their bout at UFC 90 in October of 2008. One minute and 20 seconds later, Werdum was asleep on the canvas and dos Santos had come out of nowhere to capture the interest of the MMA world.

It turned out he was only getting started. Blistering victories over Stefan Struve, Mirko “Cro Cop” Filipovic, Gilbert Yvel, and Gabriel Gonzaga, all of them coming by way of knockout or TKO, validated dos Santos as one of the most explosive heavyweight strikers in the world. His rise was so quick, and so dramatic, that not all of MMA’s fan base is fully aware yet that he ranks among the world’s best heavyweights. In his nine UFC fights, he has finished all but two opponents by strikes. Roy Nelson and Shane Carwin are the only men to have gone to decision with Cigano. Both men are known to have granite chins.

Continuing his tutelage under the Black House MMA camp, which houses some of Brazil's most gifted fighters, dos Santos has earned a reputation as one of the most feared young heavyweights in the world today.

After his fight against Roy Nelson Junior was invited to be a coach on the Ultimate Fighter. He would coach opposite Brock Lesnar and the two were supposed to meet in the Octagon after the show but Lesnar had to pull out of the fight due to injury. Dos Santos fought Shane Carwin instead and defeated him via unanimous decision. With the victory over Carwin, “Cigano” earned a title shot against Cain Velazquez.

The title fight between Velazquez and Dos Santos was shown on free TV and 8 million Americans saw Dos Santos victorious again that night. He knocked Velazquez out in under a minute.  He dispatched Mir in the second round due to strikes. He was set to rematch Cain Velasquez at UFC 155. In a surprising turn of events, dos Santos was utterly dominated through all five rounds. He was rocked several times throughout the fight and taken down at will by Velasquez. Before the fight, he was touted as having the best take down defense in the whole division, but Velasquez did not care. He lost the fight by unanimous decision.

Dos Santos would make his next appearance at UFC 160 taking on the 9 - 7 Mark Hunt in the Co Main Event. Hunt, who expressed interest in the fight after learning that Dos Santos' original opponent, Alistair Overeem, was forced to pull out of the bout with a quadricep injury, was riding a 4 fight winning streak and looking to add a victory over a top 5 heavyweight to his resume. However Dos Santos would finish Hunt with a highlight reel wheel kick in the third round of their fight. The fight also earned Fight of the Night honors.

Dos Santos again met Velasquez when they headlined UFC 166 to complete their trilogy and again fight for the Heavyweight crown. In a fight that had many parallels to their second meeting, both fighters showed tremendous heart. This time though, JDS would come up short again, being stopped by TKO in the fifth round. Their epic trilogy has been called one of the best in the history of MMA and proved that both men are two of the greatest heavyweights to ever compete.

Junior Dos Santos used to have a hair just like Cigano (gypsy).  Not literally a gyspy, Cigano was the name for a fictional character in a Brazilian Novel called "Explode Coracao". People used to make fun of him by calling him Cigano, but after awhile he got used to it and today it is his nickname.

Junior would bounce back from his second loss to Cain with a Unanimous Decision over Stipe Miocic in the Main Event of UFC on Fox 13. He would also earn a Fight of the Night bonus for his efforts.