Posh left it late before grabbing all three points having trailed to a David Mooney goal with 10 minutes to go which looked like it would send Orient back to the top of League One.
"I thought that it was a thoroughly deserved three points, we played very well, worked hard, our shape was good and we looked solid against what is a very good team," Ferguson reflected.
"They are going very well and full of confidence. We lost a poor goal, I have to say and we will have to have a look at that on Monday but to came back the way we did was excellent.
"First of all, there was the good header by Britt (Assombalonga) and then Tommy (Rowe) got the winner but I thought we thoroughly deserved the win.
"We had a penalty shout turned down in the first-half when the referee said it wasn't deliberate but I've never seen a deliberate penalty in my life. They are not deliberate, it's just a penalty but he didn't give it so you gave to get on with it.
"This win might be a turning point for us. We've had a lot of hard luck stories when we keep saying we were unlucky but we've come back here which is something we haven't done for a while.
"And it was against a team that is flying, so it's a good result. I thought that we got stronger as the game went on and as a team, we were good."
Orient manager Russell Slade was left downcast by the manner in which his side conceded the late goals.
"Losing to late goals is part of the tapestry of the journey that we are on, I suppose," he said. "This game can be very hurtful at times and it turned out to be a hard and close-fought game for both teams.
"We managed to get ourselves in front and with just a few minutes to go, we should see games out. It's something that we need to address.
"I thought that we gave a free-kick away for the first one which was a little bit clumsy and for their second goal, we've given the ball away in the middle of the park after we had decent possession.
"So really those goals were avoidable.
"We scored against the run of play really. We came up against a decent side, make no mistake about that. They were in the Championship, they are a good side and they showed that. If they had lost the game, that would have been really unfair on them.
"I thought that we started the game really well for the first 20 minutes but they came into it as the half wore on and it was a very tight game and you thought maybe that first goal was going to be a clincher. "
- Sports & Recreation
- Britt Assombalonga
- Tommy Rowe