John Mousinho’s men trailed 3-0 at the interval and never looked like finding a way back into the match, despite a system switch and using three substitutes.
Orient were comfortably the superior side and that is now five points from six matches – and here are our Pompey player ratings...
5. Jack Sparkes - 5
(Replaced by Terry Devlin on 46 mins) Should have been closer to his man for the opening goal and produced a couple of disappointing crosses. Made way at half-time in a system change, with Lane put at left wing-back. Photo: Jason Brown
6. Marlon Pack - 6
Kept trying to drive Blues on, wanting the ball, looking to get involved. One of the few who maintained his reputation. Photo: Jason Brown
7. Joe Morrell - 4
Not his usual self. Normally buzzes around influencing play, yet struggled to get a foothold on this occasion as the Blues crumbled. Photo: Jason Brown
8. Christian Saydee - 4
(Replaced by Tom Lowery on 46 mins) Won possession a few times and can always retain possession, but offered very little as an attacking force and an obvious player to replace at half-time. Photo: Jason Brown