Your fight scene has to be part of your overall narrative, not a diversion from it. The key elements of a good story—character development, rising conflict, and detailed worldbuilding—must not be abandoned just because a fight is happening. A fight can be interesting if it's well choreographed or presented in an unusual context; for example, a bare-knuckle boxing match in a medieval castle hall. However, unless the fight serves some larger narrative purpose, it should never take over the plot. A fight scene should have a beginning, middle, and end. It starts with a physical altercation that can be resolved in many different ways. Then there's a moment of stillness as each fighter assesses his or her opponent before the next thing you know they're punching and kicking each other in the chest and belly. At some point during the fight someone will probably get punched in the head which would explain why nobody else fights anymore. When the battle is over we are left with two characters who have been changed by what has happened between them. One might have gained confidence while the other has lost some; perhaps even after several hours have passed you can see signs of improvement in fighting skills. In conclusion, a good fight scene must be part of an overall great story with three essential ingredients: character, conflict, and change.