This was Fairlop's 15th win of the season and a draw from their last two games will be enough to secure the title, pipping long-time leaders Bayern Mincha to the post.
Fairlop visit struggling Temple Fortune B before finishing their season away to North London Raiders C.
Jubilant boss Aaron Dias told JC Sport: "Ahead of this game, the task was clear - four points required from three games to be crowned champions in our debut season. And now we’re almost there!
"The match was played in tricky conditions today, with the grass being heavily overgrown and the delay in kick-off due to players having to remove unwanted items from the pitch. You could tell the Dons were used to playing on this pitch but fair play to them they came at us in the first 30 minutes. But we grew into the game and snatched an undeserved lead before the end of the half.
"Today wasn’t our best performance but in some ways for me the most satisfying game of the season. We dug really deep and got the win, which at this stage of the season if the only thing that matters.
"We’ve got bags of goals in our team but what will see us over the line is our defensive ability to keep clean sheets.
"Roll on next Sunday, champagne will be on ice!"
DONS: Oli Burchell, Josh Cinna, Adam Isaacs, Ryan Kramer, Adam Lisberg, Adam Morrow, Josh Moses, Harry Moss, Jamie Nagioff, Nicky Phillips, Zach Cohen. Subs: Adam Diamond, Richard Reback, Jordan Rinsler
FAIRLOP: Jake Sanders, Mitchell Gold, Pierce Prince, Max Freedman, Daryl Rubin, Daniel Bean, Matt Berkley, Adam Goldman, Daniel Rosen, Daniel Garfinkle, James Jaconelli. Subs: Brad Porter, Kai Vale