A first-half injury-time goal from Craig Makail-Smith allowed Brighton & Hove Albion to pick up their second victory in as many Championship matches at the expense of hosts Portsmouth.
The summer signing from Peterborough United reacted quickest to Ashley Barnes's scuffed shot to turn the ball in from close range.
Gustavo Poyet's Brighton have the same number of points as league leaders Southampton but remain in second place by virtue of goal difference.
Both teams are back in action during midweek with Portsmouth hosting Reading at Fratton Park on Tuesday, August 13 while Brighton travel to Cardiff City on Wednesday, August 14.