独占鳌头

1. • to come first in triennial palace examinations (refers to the carved stone turtle head in front of the imperial palace, next to which the most successful candidate in the imperial examinations was entitled to stand) to be the champion to be the very best in any field

     idiom

Character by character

• 独(dú)alone
• 占(zhàn)take possession of
• 鳌(áo)mythological sea turtle
• 头(tóu)head