Pompey made an early exit from the Youth Alliance Cup after being beaten 5-1 at AFC Wimbledon.
They fell behind to Zach Robinson’s finish, only for a fierce Alfie Stanley (pictured) shot into the roof of the net to draw the visitors level.
But Jack Madelin, Dylan Adjei-Hersey, Robinson and Troy Chiabi all netted to ensure the Dons would progress to the second round.