Vitali Klitschko, the WBC heavyweight champion, reacts to being slapped by British boxer Dereck Chisora (behind the kerchief). (CHRISTOF STACHE / AFP / Getty Images)

The traditional nose-to-nose photo-op weigh-in that proceeds a boxing do-si-do turned sour when Dereck Chisora slapped Vitali Klitschko, the WBC champion, ahead of their heavyweight title bout Saturday in Munich. Members of the fighters’ camps had to be separated after the slap and string of insults Chisora sent Klitschko’s way. Klitschko chose not to retaliate.

“I am going to hit back on Saturday,” he said.“He will get his.”

Although Chisora, 28, said he can “smell fear” from Klitschko’s people and has predicted he will win in an eighth-round knockout, he is at a disadvantage in terms of height and reach.

“Chisora can hit, and I do, too. So I don’t see it going 12 rounds,” Klitschko, 40, said.

This isn’t the first time Chisora has caused a stir at a weigh-in. He once kissed an opponent, so perhaps Klitschko got off easy.

“We're all scratching our heads about it, to be honest,” promoter Francis Warren said. “You always expect something from Dereck — he's a character — but it's usually something that winds people up or is a bit jovial.

“So for him to get physical and aggressive, unprovoked, is surprising. But I'm sure there's method to his madness and we'll find out if the madness has paid off tomorrow night.”