With his latest KO at GAMMA 671, Gunnar Steigelmann has become the all time leader in most all time KO wins with 29 surpassing Jt Colossus with 28. 2 other fighters Renan St Juste and Raz Matazz who both competed in the lower weight classes have 27 each (if you include their super fights outside of GAMMA).
The most impressive about Gunnar is the fact that he is still competing at a high level, ranked inside the top 100 of the game despite him being 40y of age! A win in his next fight against Bubba could earn him a title shot.