BROADSTREET relied on guile and pace to outwit a Peterborough pack who looked at least two stone a man heavier and were bolstered by the experience of new recruit Jon Phillips, the former Northampton and Bedford lock.
It was 6-6 at the interval, Danny Richards trading penalties with Peterborough fly-half Duncan Low, but Street increased the tempo at the start of the second half and the visitors' desperate defensive measures granted Phillips three more opportunities to demonstrate his accuracy.
He collected two more points to frank the opening try, an admirably fluid assault launched deep in home territory by Ady Hall and rounded off by Gary Challis.
Sustained pressure led to a trademark Hall try from a scrum seven metres out, Richards again adding the points to effectively secure the game with 20 minutes to play.
And, inevitably perhaps, Street lost their momentum in the closing stages when, having been reduced to 13 men by technical indiscretions, they allowed Peterborough to snap up a consolation try via skipper Cook.