In a match when neither keeper had much to do, particularly the visitors, Romain Esse’s 13th-minute goal was enough to earn Millwall victory.
Pompey raised their game in the second half, with Sammy Silvera and Zak Swanson catching the eye, yet they couldn't carve out enough opportunities to force home an equaliser.
And here are our Pompey player ratings...
5. Cohen Bramall - 7
(Replaced by Marlon Pack on 69 mins) Reined in his useful forays down the left and focused on defending, which he did solidly. His pace and mobility are big assets, always providing a useful safety net. Photo: Jason Brown
6. Andre Dozzell - 8 - MOM
Calmly slotted a shot through a ruck of players to level, then later popped up in the Blues’ penalty area to thwart an attack. That summed up what he offers Pompey and it was another tireless display. Photo: Jason Brown
7. Freddie Potts - 7
Not as influential as usual, given little time of the ball through Millwall’s physicality. Work-rate still there, though, and kept on running. Photo: Graham Hunt
8. Matt Ritchie - 6
(Replaced by Harvey Blair on 69 mins) - Helped keen Pompey defensively tight, aided by that magnificent work-rate. Barely made any inroads as an attacking force, although did pop up in the 65th minute to hit the post. Photo: Jason Brown