The act of completely and undoubtedly succeeding in an endeavor, to an absurd extent.
Eric: "Hey Jim, how did the interview go? You think you got the job?"
Jim: "I absolutely beasted it! Couldn't have gone better. I could have shat in the interviewers eye and he still would have shook my hand and beamed like he was getting an immoral blowjob at Disneyland."