Underdog
rjuːəfɔː ʒɛθɹiː rjuːəfɔːʒɪθɹiː lɪtəɹəli ðə wiːk
In Chinese 弱者 (ruòzhě) - Literally: the weak
A person or group considered to be the weaker one in a contest or fight.
Example
"The underdog team surprised everyone and won the championship."