Usually, when cichlids fight as a pre- spawning behavior, their colors will intensify but they "lip lock" not really "fight". If they are fighting, there is usually attacks to more parts of the body including the fins and tail. These will be shredded in a fight but not usually in a pre-spawn behavior. While this is the norm, it's not always the case. Many breeding S.A. cichlids look like they went 10 rounds in a heavy weight fight right before they start spawning together so it's up to you whether you want to allow this to continue or separate the pair. Not knowing what genders you have makes this more difficult to advise which move is best.
Hope this helps.