LAS VEGAS — Justin Gaethje stopped Michael Johnson with punches in the second round of a savage fight Friday night, remaining unbeaten in a UFC debut that was every bit as spectacular as expected.

Gaethje (18-0) got wobbled and hurt by Johnson during a frenetic first round and again in the second, but the UFC newcomer took control of the fight after staggering Johnson midway through the round with a knee to the body.

Gaethje finished the veteran Johnson (18-12) with primal punches and knees that elicited gasps from the T-Mobile Arena crowd.

He celebrated by climbing onto the edge of the cage and doing a backflip onto the canvas, but only after slipping and falling in his first two attempts. Fans chanted Gaethje's name during the celebration.

"Who's next?" Gaethje asked the crowd. "Where is my equal? Where is he?"

Jesse Taylor stopped Dhiego Lima in a second-round choke to win the finale of "The Ultimate Fighter," the UFC's long-running reality competition show. Taylor earned a spot back in the UFC nine years after he was dropped from the promotion amid questionable outside-the-cage behavior.

But Gaethje's debut was the main event in the first card of the UFC's International Fight Week, and the veteran seized the spotlight.

Gaethje has been considered one of the top MMA prospects outside the UFC for several years. The former college wrestler was the lightweight champion in the World Series of Fighting, where he was one of that promotion's top attractions for the past four years.

Despite his wrestling background, Gaethje gained his fame as a willing brawler with potent fists and a reckless approach to the sport. He stopped 15 of his first 17 MMA opponents, including four straight heading into his UFC debut.

Johnson has been a UFC regular for six years, but he entered the cage in need of a victory after losing three of his previous four. The fighters didn't disguise their mutual contempt during the promotion of their bout, but embraced warmly afterward.