A single Ludovic Sylvestre goal was enough for a victory which leaves Ince's side five points clear of the relegation places with four games to play.
But it was grieving defender MacKenzie - on loan from MK Dons and playing for a permanent deal - who impressed the manager.
Ince said: "Gary MacKenzie was outstanding. He lost his granddad in the week and we said we'd dedicate the win to him.
"We said he could have a couple days off but he wanted to be part of it and considering the situation, he was brilliant.
"Loads of players are out of contract. We've got some very good players out here and I've said to them from day one, as soon as get to where we need to in this league, we'll sit down and talk about the future. But he's certainly not doing any harm."
Safety is not assured yet, according to Ince, who said: "It's a crazy league, isn't it? We can't count our chickens at this moment in time but what I do know is that it was a vital three points - a must win game."