Most NBA players don't really want to fight. Jalen Rose calls them "Hold me back!" players. they bump, throw in a dirt shot and flex because they know it will never come down to actual blows. There are a few guys that don't need to do that because everyone knows they will retaliate.
At the top of that list, we have James Johnson. When Serge Ibaka gets annoyed and starts trouble, but then realizes who is on the other side, this is what happens.
Why did this happen? Ibaka remembered his Johnson's nickname is "Bloodsport" and that he has a 7-0 MMA record and a 20-0 kickboxing record. Johnson not only has the will but a record that proves he has the skill.
Johnson comes from a martial arts family. Both of his parents are black belts and all of his eight siblings are black belts! It is obvious martial arts were not optional in the Johnson household, and James feels the values he learned are so important this is the one thing his son Naymin will have no choice over (via Grantland):
“What martial arts did for me growing up — in life, in school, and athletics — I feel like that’s the only thing that I’m going to force Naymin to do,” Johnson said. “I think I’m going to put my foot down strong on that.”
Many people are skeptical when they hear his record. You don't imagine a 6-8 guy being very nimble and precise. Chris Paul was like that, so he challenged Johnson back in 2006 "I bet you can't kick my face." Johnson executed a roundhouse kick, whipping just in front of Paul's face. “I swept it by his face a little bit.”
His reputation follows him wherever he goes, so you can be sure if James Johnson is on the court, there won't be any fighting. People know Bloodsport is on the court.