What was essentially a reserve side - two changes from Monday's team at Southampton - struck back in some style after falling behind at London Road and Colin was glad of the test.
Fry's Posh delight
"I thought it was a very good exercise and I think we were tested defensively," said Colin. "In some games you might not always get that in the reserve league.
"It is obviously worthwhile, coming and playing against people who are seasoned and experienced in the second division.
"Eventually we got to grips with it. We got our goals possibly when Peterborough were playing slightly better. From that point on we were put in a very good position."
Colin conceded that a slow start might have been down to some of his players being a bit 'leggy' after Monday's tough examination, but the structure of the week determined that matches doubled as training.
"They might have been. It has not been ideal the way we've gone about this. As I said earlier in the week, the games were going to be the players' work and training this week. It keeps them ticking over, I'm sure they would much rather be playing games like they've played in - Southampton on Monday and up here tonight on good pitches in a main stadium - against good opposition.
"They are going to get far more benefit from this than they are listening to me on the training ground."
Colin Calderwood was satisfied with the work-out his team had in the 4-1 win at Peterborough and was happy with the way they dealt with the threat of a league outfit.