Marsh's second half header was enough for the Silkmen to maintain their unbeaten home record - watch match highlights here.
The 23-year-old struggled for games at Dover last season, failing to score for the club, before heading out out on loan to National League South Welling United.
But as happens so often, Marsh came back to haunt the Whites last night, and was thrilled with his involvement.
He said: "I think the game went really well. It was against my ex-team to so it was nice to get a goal and win the game. It makes it much more sweeter, that was the first time I'd played against them to it was good to score.
"I tried to get away from my man for the goal. I know where the ball is going to go, it zipped off the pitch and I just put my head in and got the goal.
"We haven't lost at home so we're doing very well. We need to keep on going and make this a fortress."