World class kickboxer and undefeated boxer and mixed martial artist Tyrone Spong has taken to Twitter to call out ONE heavyweight champion Brandon Vera.

Spong laid down the gauntlet with the following Tweet:

ONE Championship CEO / Founder Chatri Sityodtong was also tagged. The Singapore promotion has been aggressively recruiting talent in recent months.

Signings have included some high-profile additions to the heavyweight division as well as several world class kickboxers. Spong hasn’t competed in MMA since 2013 but his record stands at 2-0 with both those wins coming in the PFL, or WSOF as it was called at the time.

Spong has not competed in kickboxing since 2014 when he suffered a serious leg injury in a Glory light heavyweight title fight against Gokhan Saki. In recent years he has been focused on his boxing career, putting together a 14-0 record and winning regional titles with the WBO and WBC.

Spong trains at Sanford MMA in Florida with Aung La Nsang. The Burmese star is obviously the one who inflicted the loss on Vera referred to in the Tweet.

Spong’s manager is Ali Abdelaziz. The Dominance MMA CEO recently announced a partnership with ONE and has already been responsible for some big deals including a new contract for Cosmo Alexandre and the signings of heavyweights Marcus Buchecha and Amir Aliakbari.