After a close game in round three at Mansfield, Rodgers put out a fairly strong side at Oldham but containing youth with a massive trip to Arsenal in midweek.
Oldham had the dream start as a stray hit across the Liverpool box came to M'Changama who swept in a cross which met the head of Matt Smith and flew past Brad Jones to give the home side the lead inside the second minute.
The away end cheered again soon after as a Henderson free-kick glanced off Suarez before crossing the line but sadly for Liverpool the effort was chalked off for offside.
Oldham continued to push for another lead and they were rewarded minutes before the break as poor defending from Liverpool saw Jones spill a cross from Wabara which dropped sweetly for Smith to smash home and seal a brace and send his side 2-1 up into half-time.
After the interval, Liverpool should have had an instant leveller but Borini hooked over from Robinson's cross and the miss proved to be costly as Oldham went two goals clear through nice play which saw Winchester cross to the far post to meet the oncoming Wabara who looped a header over Jones to send the home fans into a rapturous roar.
The tie could have been sealed as Baxter broke through the Liverpool defence after a Coates mistake but hit his shot straight at Jones and this saw a double change from Liverpool with Gerrard and Downing replacing Wisdom and Borini.
The changes sparked a comeback which came from an unlikely source as the ball broke on the edge of the Oldham area to Joe Allen who hit a superb volley which deflected past Bouzanis and give Liverpool hope in the 79th minute.
Gerrard hit a long range shot which cannoned off the crossbar to groans from the away following and soon the final whistle sounded and Oldham had caused a gigantic 'cupset' leaving Liverpool to go home after being outperformed.