Midfielder Kane Ferdinand headed home the only goal of the game and his first for Peterborough on the stroke of half-time as Ferguson's troops extended their unbeaten run to five.
The Posh still sit third from bottom but are just a point shy of Sheffield Wednesday, who lost 2-0 to leaders Cardiff, while Barnsley are another point away.
And, with eight games of the season left, Ferguson believes they are going to need more than a point a game.
"I thought my players were magnificent," he said. "It's a big three points. In the first half I thought Blackpool were the dominant team.
"We were a little bit lucky, Bobby Olejnik made two or three top saves and we scored with only our real clear-cut chance of the half. But in the second half we were far better.
"It gets us to 42 points. No one can even start to predict how many you need to stay in the league, but no way is 50 going to be enough.
"But we are on a good run, we are unbeaten in five. Before the game, I showed the players the league after seven games and I showed them the league now.
"For us to be in the position we are in, they deserve credit for that. We threw away 21 points at the start of the season. But we are catching up. It's one of those seasons.
"I have got a great bunch of lads, they give me absolutely everything. This is why you are in it. It's going to be a really exciting finish and I'm looking forward to it."