Goals from Tommy Rowe, Tyrone Barnett, Grant McCann, from the penalty spot, and Britt Assombalonga gave over 2,000 Posh fans plenty to cheer about as their team made it nine goals in five days, coming after their crushing 5-1 midweek Capital One Cup victory at Colchester.
Dean Leacock had opened the scoring for County in the firsthalf, while substitute Yoann Arquin scored a late consolation penalty in a game which got away from the home side after a decent first period.
Ferguson admitted that although he is pleased with his side's start to the season, he still feel there is a lot more to come.
"It was a good result and you've always got to be happy with three points. I wouldn't say it was a great performance and I'm not happy with conceding two goals," he said.
"But it is a very difficult place to come so we've got to be happy with a win. I just wanted us to do the basics right as it's very much a league where the team who make the least mistakes will win games and when we do the basics right we are a good team.
"We need to improve on that if we want to do what we want to do. We've got periods in the game when we just go up a level, which is too much for teams at the moment. "But I'm delighted with the start we've made - three games, three wins and 10 goals. You can't ask more than that."