[1] Lighty made his K-1 debut as a tournament reserve fighter on the August 2004 K-1 card in Las Vegas, Nevada, scoring a second-round knockout over Frank Cota.

He knocked out Tatsufumi Tomihira by a high kick in the quarterfinals and beat Chalid Arrab by a unanimous decision in the semifinals.

In the final bout, Lighty remained on his feet, but took a considerable amount of punishment from the Russian kickboxer Ruslan Karaev and lost the fight after three rounds of action.

After 2007, there were not many K-1 fights held in the United States and Lighty decided to switch from kickboxing to mixed martial arts.

He made his professional debut on the reality show TapouT and won that battle by verbal submission in the first round over Derek Thornton.