Goalkeeper Dion-Curtis Henry produced three superb first half saves as the Posh under 18s claimed the derby day honours.
The Peterborough United under 18s took their goal tally to 12 from three Youth Alliance League matches as Dave Robertson's men eased past local rivals Cambridge United 3-0 on Tuesday afternoon.
Goalkeeper Dion-Curtis Henry took the plaudits in the first half with three outstanding saves to keep the Us at bay as the hosts got the better of a difficult surface.
It was goal-less at the interval, but after a stern team-talk, Posh came out all guns blazing in the second period and on the hour mark opened the scoring through in-form Jack Friend. The former Wisbech Town front man took his personal tally to seven from three games as he fired home via the inside of the post.
Tye Phillips doubled the lead after a forceful run from Jonathan Edwards in the build-up, before Edwards himself coolly slotted past the goalkeeper after racing clear to complete the scoring.
Friend was denied a second by a superb save from the Cambridge shot-stopper, while Phillips somehow missed from close-range when it looked easier to score.
Robertson said: 'It turned out to be an excellent win and the lads put in a much improved display in the second half. I was disappointed with the way we started the game and we need to start a lot better on Saturday at AFC Wimbledon.
'Dion made three superb saves to keep the scores level before the break and he deserved his clean sheet. It was difficult for us in the first half, Cambridge made the game very scrappy and we couldn't get our passing rhythm going, but we improved after the break.
'It is always pleasing to win a local derby. Cambridge were taking the game seriously, their first team assistant manager Alan Neilson took the game and the rest of their coaching staff were there to support their youngsters.'
Posh: Henry, Luto, Ward, Hood, Maslen-Jones, Lee, Keating, Adebayo-Rowling, Friend, Edwards, Phillips.
Pictures by Chantelle McDonald.