Upstaging refers to the act of drawing attention away from someone else's performance or achievement. If you're looking for synonyms for upstaging, then there are a variety of options to choose from. One possibility is "overshadowing," which conveys a sense of casting a large and dominant shadow over others. "Eclipsing" is another relevant synonym that suggests that one person or thing is outshining another. Other options include "outshining," "outlining," "dominating," or "outperforming." Each of these words conveys a sense of someone or something taking center stage, leading the way, and leaving others in the background.