After seeing his side frustrated on a freezing East End night, the former Tottenham flyer led the way with the opener that was the catalyst for a goal avalanche.
Having clocked up their 15th draw of the season against Walsall on Saturday, West Ham simply had to get back to winning ways in this, their 35th start of the campaign.
But the doomed Dons froze the Hammers out in the early stages and try as they might to chip away at the visitors dogged defence, Pardew's men could find no way through.
Indeed, they had to wait until midway through the half before former Dons duo Nigel Reo-Coker and David Connelly finally carved out an opening only for the Irish international striker to sky over from inside the six yard box.
Then as the half hour mark approached Connelly turned provider but Bobby Zamora saw his acrobatic volley held by ex-Hammer Steven Banks.
However, two quick fire goals in the space of 90 surreal seconds brought West Ham in from the cold.
On 37 minutes, Etherington popped up at the far post to steer home the overlapping Marlon Harewood's deep low cross.
And as Stuart Murdoch's men tried to regroup Zamora cut inside Peter Hawkins before unleashing an unstoppable 18 yarder that flew past Banks to give West Ham an improbable two goal interval lead.
Just after the re-start, Harewood unselfishly squared to Zamora who wastefully scuffed to Banks but West Ham did not have to wait long for an inevitable third.
On 49 minutes, Michael Carrick's defence splitting pass released Etherington who outpaced Jermain Darlington before slotting wide of the exposed keeper.
Having ransacked Wimbledon for Connelly, Reo-Coker and substitutes Jobi McNuff and Adam Nowland, West Ham were now plundering goals galore.
And on the hour mark Harewood's clever flick opened the door for Etherington whose pass enabled the dignified Reo-Coker to squeeze a low eight yarder inside the near post to claim his first goal since his arrival from Milton Keynes with minimal fuss.
The celebrations were louder, though, when Etherington burst on through Connelly's well weighted 70th minute pass to claim one of the match balls with a clever angled chip over the advancing Banks who by now was finding himself as dejected as the Dons downbeat 190 travelling fans.
"After weathering the storm for 35 minutes I didn't enjoy that at all," said Stuart Murdoch after seeing his skeletal team bravely battle for the entire 90 minutes.
"West Ham are a big side but, then again, they've got half of my players!
"As for whether they are capable of automatic promotion, you have to put this result into context because they are going to have to play much better sides than us between now and the end of the season."