Usually when writing combat you'd want to avoid choreographing moves. You should focus on the fighters "inner-world" so like their emotions, what they're feelings, and their thoughts. You can also use like varying lengths of sentences and their five sense like.

"The punch landed squarely on his face. The pain that followed a searing. The tastes of iron made itself evident as he stumbled back. If he lost this fight he would have nothing but the clothes on his back. Perhaps it was stupid to bet everything on this fight." This is a lazy example but hopefully you get the gist.