View the photos from a narrow loss at Kenilworth Road
Pompey twice fought from behind before being beaten in an entertaining top-of-the-table clash at Luton.
The hosts dominated the opening 45 minutes and James Collins' strike ensured they deservedly led at the interval.
But the Blues were much stronger in the second half and Ronan Curtis levelled, only for a Collins penalty to restore the Hatters' advantage.
Pompey hit back again through impressive debutant Omar Bogle, but George Moncur struck a late free-kick to ensure the visitors left with nothing.