Watch: UFC Rookie Scores 15-Second KO at UFC Shanghai

The UFC made its long-awaited debut in mainland China on Saturday morning, and the company was undoubtedly hoping some of the local talent would come through with crowd-pleasing performances.

Song Kenan delivered that in a big way, posting a 15-second knockout in his first fight in the Octagon.

Shortly after the bell, Song clobbered his opponent, Bobby Nash, with a right hand to the temple. He went down on contact, and went down hard, but the punishment didn't stop there as Song poured on heavy ground-and-pound.

When the referee finally stepped in, Nash was so rocked that he held onto a single-leg takedown for a full 10 seconds before realizing the fight was finished.

That's about as impressive as a UFC debut can get. Song, 27, will be fun to watch moving forward, and he lived up to his "Assassin" nickname in this one.