Justin Greskiewicz

Justin Greskiewicz is one of the top pound for pound Muay Thai fighters in the country. He fights anywhere from 140-147 lbs, but has fought as light as 138 lbs and as heavy as 155 lbs as a professional. Justin has been fighting since June 2005, and has amassed over 65 fights to date, 25 amateur and 40 professional.

Justin has fought some of the top fighters in the world, including Malaipet Sasiprapa, Kevin Ross, Salah Kalifah, Matt Embree, Shane Campbell, and Liam Harrison. Justin is one of the few East Coast fighters who has earned a WBC title belt, an international title agains the WBC UK champion, Bernie Mendietta of England. Justin has competed in some of the nation’s largest promotions, including Lion Fight and K-1.


Justin has been a staple in the Muay Thai community, working to grow Muay Thai in America. In addition to competing often on the country’s biggest stages, Justin is the owner and head coach at Stay Fly Muay Thai in Philadelphia, PA. He is also a NJSACB referee and judge, has worked as a judge at Lion Fight, and as a referee for the WKA.


Justin works as a striking coach for some of Philadelphia’s top MMA fighters. His clients include UFC fighters Charlie Brenneman and Zack Makovsky, as well as Bellator’s Will Martinez. Justin also had the pleasure of being the main event on both New Jersey and Pennsylvania’s first full rules Muay Thai events, historical milestones he is very proud of.


Justin’s love for the sport of Muay Thai makes him eager to share his knowledge and passion with those who have a chance to train with him. Whether a beginner student, aspiring fighter, or established professional, Justin can help you expand you knowledge and love for Muay Thai.