Raul Rosas Jr, who is 17 years old, won the Contender Series and was given a contract, making him the youngest fighter in UFC history.
Rosas extended his unbeaten streak to 6-0 after dominating Mando Gutierrez, 25, throughout three rounds with his grappling techniques.
Before the bout with Gutierrez, all of Rosas' victories had been by way of submission; the Mexican had made his amateur debut at the age of 15. Chase Hooper, a former contestant of the Contender Series who received a UFC contract at the age of 18, formerly held the record that Rosas has now beaten.
Rosas not only astonished UFC president Dana White by nearly ending Gutierrez in the first round with a powerful Suloev stretch submission, but he also displayed some outstanding striking ability throughout the contest.
After winning, he said: "I knew I was gonna get that contract. I've been saying it since the beginning. Since I was born, I knew this was gonna happen. "Everybody shouldn't be surprised. I'm the new king in here, so I'm coming for that belt now. I'm gonna be champion when I'm 20."
Rosas, who turns 18 on October 8, has five years to shatter the UFC record for the youngest champion ever. The record is presently held by former No 1 in the pound-for-pound rankings Jon Jones.