两人要一决雌雄怎么办？决斗呀！challenge sb. to a duel - 提出要和某人决斗
如果两人势均力敌，那么可以用"neck and neck"这个短语来表达：
neck and neck (with somebody) informal if two competitors or groups are neck and neck in a competition or race, they are level with each other:
Opinion polls show the two main parties are running
neck and neck.
如果能无人能敌，无人能出其右，则可以说"be second to none" 或者"Be without equal/have no equal"
be second to none: to be the best:
The quality of Britain's overseas aid programme is second to none.
be without equal also have no equal
formal to be better than everyone or everything else of the same type:
His paintings are without equal.
不能望其项背: can't hold
a candle to somebody/something informal if something or someone
cannot hold a candle to something or someone else, they are not as good
as the other thing or person:
No other singer can hold a candle to her.
be a cut above something to be much better than someone else or something else: - 比别人强得多
The movie is a cut above recent thrillers.