When it comes to finding synonyms for the phrase "going up against," there are several options available. The first thing to consider is the context in which the phrase is being used. If it is in the context of a competition or a debate, then some alternatives for "going up against" could be "challenging," "competing," "rivaling," or "confronting." In a more confrontational context, synonyms like "fighting," "battling," "opposing," or "resisting" can be used. Other potential synonyms to consider include "combating," "engaging," "dueling," or "squaring off." Ultimately, the appropriate synonym for "going up against" will depend on the specific situation and the desired tone of the communication.