Dictionary / Vocabulary / 対抗馬
たいこうば
rival candidate; rival; opponent; rival horse
本命と対抗馬が競り合ったお陰で、ダークホースの彼が漁夫の利を得たってわけだ。
Since the favorite and his rival were running against each other a dark horse like him was able to pull out in front.
彼の馬は着々と対抗馬に追いついた。
His horse gained steadily on his rivals.