The Posh under 18s were beaten 4-1 by Leicester City at the King Power Stadium.
The Peterborough United under 18s were beaten 4-1 by Leicester City at the King Power Stadium on Wednesday evening in the fourth round of the FA Youth Cup.
On a wintry evening with snow falling throughout, the Foxes made the best of the conditions and progressed into the fifth round where they will face either Hull City or Northampton Town.
Brown, who had earlier tested Stuart Moore with a powerful volley, was a constant threat and alongside the goalscorer were Posh's stand out performers on a night that the Foxes proved just too physical.
The third goal came from the spot after Jack Hendry was adjudged to have felled Dylan Casey and Robert Paratore coolly converted from the spot.
It was 4-1 when centre back Jamie Anton powered home a header from a Jak McCourt corner kick. Leicester were a threat throughout from set-pieces with a physical presence causing problems for the Posh back-line.
Coulson and substitute Regan Carthey both went close towards the end while Hendry headed a corner kick wide of the target.
Posh: Lynch, Richens, Burgess, Anderson, Hendry, Sage, Coulson, Wood (sub Carthey), Lawlor, Gordon, Brown. Unused subs: O'Reilly, Sparrow, Carter, Wright.