Christian Burgess scored his third goal of the season to fire Portsmouth to a 1-0 win at home against Sky Bet League Two promotion rivals Luton.
Burgess' thumping header from Carl Baker's corner 14 minutes before half-time handed Pompey victory at a sold out Fratton Park.
The win would have been more commanding but for Gary Roberts missing a late penalty.
Gareth Evans and left-back Enda Stevens both went close to doubling Pompey's lead as the hosts dominated the first half.
Evans should have done better in the opening seconds of the second half when he failed to convert a free-header from Baker's cross.
Roberts passed up the chance to seal the points in stoppage-time when he blazed over from 12 yards after Noel Hunt had been fouled by Olly Lee.
The win completed a double for Pompey over Luton following their 3-1 triumph at Kenilworth Road.
The Hatters' misery was compounded as midfielder Cameron McGeehan was taken to hospital after sustaining a 16th-minute injury in a challenge with Pompey captain Michael Doyle.