Bradley Tarbuck was the hat-trick hero as Pompey Academy reached the semi-finals of the FA Alliance Youth Cup with a 5-1 win at MK Dons Academy.
The striker helped the young Blues recover from a goal down, while further strikes by Conor Chaplin and Lewis Horsburgh sealed the tie.
Under-18 manager Paul Hardyman was forced to call up three under-16 players because of injuries, while keeper Lewis Ward started after joining on loan from Reading.
The changes looked to have impacted on Pompey early on and they fell behind on three minute as Jon Usae created a simple tap-in for Mason Spence after Ward had dropped the ball.
But the Blues came out a different side after the break and grabbed a deserved leveller on the hour thanks to an individual run and strike by Tarbuck.
Tarbuck was on the scoresheet again moments later when he took Nick Awford’s pass into his stride to rifle the visitors into the lead.
With 10 minutes to go, Dons defender Luke Tingey was sent off for a foul on Horsburgh. And from the resultant free-kick, Tarbuck fired home to complete his hat-trick.
Tarbuck then became creator to enable Chaplin to ram home number four. And a fine win was sealed when Horsburgh blasted a fifth to move Pompey into the last four.
Pompey Academy: Ward, Close, Medway, Awford, Warren, Field, Maloney, Branford, Horsburgh, Tarasenko, Tarbuck. Subs: Kim, Chaplin.