Posh left it late before goals from top scorer Craig Mackail-Smith and defender Grant Basey in the 85th and 88th minutes secured the points despite a below-par performance.
Ferguson said: "We knew it was going to be a tough game. Yeovil are a hard team to come and beat at their place.
"I thought they played well on the night and we didn't play great but we did put our bodies on the line, dug in and were resolute.
"We said at half-time that we would get chances. With Craig (Mackail-Smith) in the team you will always get chances. He got one and scored.
"We had two just before that which we probably should have scored but in the end we've battled to a win that I think is as good as any we've had this season. We've played and lost, but that's football, isn't it?"
Source: PA
Source: PA