go up against

go up against (someone or something)

To face a particular competitor, trial, or test. I can't believe I have to go up against the valedictorian for this award—obviously, she's going to win!
See also: go, up

go up against someone

to compete with someone; to face someone in competition. She is going up against Rodney in the spelling bee. The champ went up against the challenger in a match last Friday.
See also: go, up