mop up the floor with (one)
To easily and deftly beat up or defeat one. Primarily heard in US. Although he wasn't favored to win the race, Jack really mopped up the floor with his competition. If the two fighters were in their prime, Balboa would mop up the floor with Dixon.
mop up the floor with
Also, wipe the floor with. Defeat thoroughly, overwhelm, as in The young boxer said he was sure to mop up the floor with his opponent, or I just know we'll wipe the floor with the competition. [Late 1800s]