Aberdeen striker Rory Fallon had came off the bench to score an injury-time penalty to make the score 3-3 at Pittodrie but it was the part-timers who held their nerve to progress to the quarter-finals by winning 4-3 on penalties after Ridgers saved Chris Clark’s decisive spot-kick.
Tynecastle legend Robbo, whose team beat Dunfermline in the previous round, said: “Mark Ridgers was obviously the star of the show.
“We have brought him in on loan from Hearts and how he is not the Scotland under-21 goalkeeper I don’t know as he has been out playing 50 or 60 games at first-team level down the leagues.
“He has not been given the chance yet but hopefully something like this will give him the opportunity.”
East Fife’s goals in normal time came from ex-Hearts player Ryan Wallace, on-loan Jambo Matthew Park and another former Tynecastle star Robert Sloan.
The home team threw away a two-goal advantage in the shootout but Park’s penalty ultimately proved decisive when Ridgers made is save from Clark.
Aberdeen captain Richard Foster, meanwhile, admitted the defeat ranked amongst his worst experiences as a player.
The Dons have been no stranger to cup exits at the hands of lower league teams in the past few seasons, with Dunfermline, Raith Rovers, Queen of the South, Dundee and Queen’s Park all beating them.
“I can’t describe how much it hurts,” added Foster. “I have been involved in games before where Aberdeen have been beaten by lower league opposition and this one is right up there with the sorest.
“I don’t know what to say, it is just horrible.
“We were slack all over the pitch. If we defended like that in the SPL we would get absolutely crucified.
“The goals we lost were terrible. We created so many chances but we were shooting from 30 or 40 yards. Nothing went right in the match.”