A poor second half defensive showing proved costly as the Shrimps shipped six goals at the Shay.
Paul Mullin gave Morecambe a fifth minute lead which they maintained until half time.
But two quickfire second half strikes from Kosylo and MacDonald saw the Shrimps fall behind.
A second Mulin goal on 55 minutes restored parity but then things went wrong as the FA Trophy winners scored four goals in the final half half hour through Garner (58), Denton (69) and two from Peniket in the final seven minutes of the game.