World Series of Fighting lightweight champion Justin Gaethje will look to defend his long-held belt against Luiz Firmino on Dec. 31 at WSOF 34, promotion officials announced Tuesday. Gaethje's original opponent, Joao Zeferino, withdrew from the title bout earlier this week due to an undisclosed injury.
Gaethje (16-0) is WSOF's longest reigning champion and one of the promotion's most talented fighters. The 28-year-old Arizona native has racked up a flawless 9-0 record inside the WSOF cage while successfully defending his lightweight strap five consecutive times since 2014 -- a run highlighted by a pair of thrilling victories over Luis Palomino and a decision win over Melvin Guillard.