n.
头号对手

A Chinese sports expert insisted that judging from their training methods,Liuxiang is more likely than his arch rival Cuba\'s Dayron Robles to grab gold in the men\'s 110m hurdles in the Olympic Games.
我国一位体育专家称，从训练方法看，刘翔比他的头号对手古巴选手罗伯斯更可能获110米栏冠军。

We whomped our arch rival in the season\'s climactic football game.
我们在该季最精彩的足球赛中打败了我们主要的对手。

The odds are in the favor of the estate developer than its arch rival in the land auction.
在土地拍卖中，该地产发展商成功投得的机会较主要对手高。