Jack Redshaw and Jamie Devitt did the damage just before the interval and Amond’s spot-kick in stoppage time confirmed their survival after Wycombe lost at Bristol Rovers.
The hosts began stronger with Chris Arthur narrowly curling a free-kick wide in the opening exchanges.
But they were hit by two quickfire goals just before the break, first Redshaw nipping in after confusion in the area to rounding Seb Brown and score his eight league goal of the season.
And a minute later Redshaw took advantage of a slip from Darren Jones to make his way down the left before crossing to strike-partner Devitt to slot home.
Wimbledon came from 2-0 down to draw their last home match and they pressed for an equaliser after the break, Jack Midson firing over from close range following Kwesi Appiah’s flick.
But Morecambe held out for their first win in 10 and first clean sheet since Boxing Day, Amond sending the keeper the wrong way in stoppage time from the spot.