Paul Cook felt Pompey were handed a slice of fortune as the visitors snatched the points at Luton.
The Blues boss believed a draw would have been a fair outcome as his team picked up a 2-1 success at Kenilworth Road.
Matt Tubbs snatched it at the death after coming off the bench for Cook’s men.
Gareth Evans had opened the scoring for Pompey, before Craig Mackail-Smith levelled from the penalty spot early on.
Cook thought it was an entertaining clash but his team weren’t at their best.
He said: ‘I didn’t think we played well.
‘We started well and were controlling the game but got sloppy.
‘But we didn’t just take what we had.
‘You don’t bring on Tubbs, McGurk and Chaplin to see the game out.
‘In a way the lads got their rich reward for not winning at Crawley.
‘I felt all week it would be a good game and it was a good game, but we didn’t deserve to win.’