“决雌雄于”可以翻译为 “determine the outcome/winner between ... at” 或 “decide who is superior between ... at” ，具体使用时可根据语境灵活调整。例如：
They will determine the outcome between them at the competition.（他们将在比赛中一决雌雄。）
The two teams plan to decide who is superior between them at the final match.（这两支队伍计划在决赛中一决雌雄 。）