Orient made it 10 home matches unbeaten after a 4-0 thrashing of promotion hopefuls Sheffield Wednesday.
The Owls almost took the lead in the first half when a header from Chris Sedgwick was nodded off the line by Charlie Daniels.
But Orient produced a four-goal salvo after the break to completely overwhelm their opponents.
They opened the scoring four minutes after the interval after Gary Teale had been adjudged to have handled a header from Alex Revell and Ben Chorley drilled the spot-kick into the net.
They doubled their advantage 10 minutes later when 17-year-old Spurs loanee Harry Kane - making his first senior start - stole in unmarked behind a static defence to tuck in a Dean Cox free-kick.
Orient piled on the pressure and two goals in three minutes completely killed off the Owls. After 79 minutes Revell rose unmarked to nod home a Daniels cross before Paul-Jose Mpoku drilled a free-kick from 25 yards past the hapless Wednesday goalkeeper Nicky Weaver.
Copyright (c) PA Sport 2009, All Rights Reserved.
Do YOU want to write for GiveMeSport? Get started today by signing-up and submitting an article HERE: https://www.givemesport.com/writeforgms