look up any word, like fleek:
 
1.
the underdog favorite - an oxymoron that describes a person, or group of people that are expected to win an event simply because they have gained popularity by being a surprise contestant.

For example:
The Indianapolis Colts became the underdog favorite to win the Superbowl after defeating two heavily favoured opponents to become AFC champions.
Jennifer Hudson was kicked off of American Idol, but when on to act in "Dreamgirls" and eventually became the underdog favorite to win the award for Best Supporting Actress.
by Scott Wood - Film Critic February 26, 2007