The opposite of "most championed" can vary depending on the context. Generally, antonyms for championed include condemned or criticized. If the focus is on popularity or support, then rejected, ignored or unpopular may be appropriate antonyms. If the emphasis is on success or achievement, then antonyms for championed could be defeated or failed. In some cases, where championed means to defend, protect, or promote, antonyms could be attacked, opposed or opposed. Overall, the antonym for "most championed" ultimately depends on the specific context and meaning of the term.