The 4-3 defeat leaves the Bully Wee languishing in fourth place in the League Two table - a massive 13 points adrift of leaders Forfar and six behind second-placed Arbroath.
And the Broadwood boss admitted he feels the defeat has ended their chances of winning the title and automatic promotion.
Indeed they are now only just staying in the play-off spots, three points ahead of fifth-placed Annan who visit Broadwood on Hogmanay.
Ferguson said: “We had the game won but it’s just joke defending for the last two goals. That’s it, that’s all I can say.
“We’re controlling the game with 10 minutes to go then it comes to the guy who’s made a mistake constantly for the last six weeks.
“He’s made a mistake every week so I’ve got a decision to make on Saturday. He doesn’t pick up his man and it’s schoolboy defending.
“It’s not acceptable, it’s stuff we work on. At times a winger or full-back gets time to swing a ball into the box, the defenders have a responsibility to follow their man and we just don’t do it.
“It’s back to the wall stuff for the last couple of minutes, another ball into the box and the smallest guy on the park heads it into the net.
“I’m sick of the defending. We work on it Tuesday and Thursday in training every week.
“The title is gone for us. Forfar, they’re not a great team but what they are is a strong and physical team.
“I don’t see them losing four or five games before the end of the season.”