beat the pants off (of) (someone)
slang To defeat someone decisively in a competition. Despite using the word "pants," this phrase does not involve literally stripping off someone's clothes. The final score was 17-1? Wow, we really beat the pants off that team!
beat the pants off
Also, beat hollow. Win decisively over someone, outdo. For example, When it comes to the Patriots' Day parade, Lexington beats the pants off the neighboring towns , or This beer beats the other brands hollow. Both phrases use beat in the sense of "surpass." Pants off has served as an intensifier since about 1930; the variant dates from about 1775.
beat the pants off
prove to be vastly superior to. informal 1990 Paul Auster The Music of Chance ‘Not bad, kid,’ Nashe said. ‘You beat the pants off me.’