Pompey's season hit a low as they crashed out of the FA Cup after a 3-1 loss at Brighton.
The Blues were comprehensively outplayed as they bowed out of the tournament they reached the final of last season.
Steve Cotterill's men could have no complaints at the outcome of the game as Gus Poyet's side dominated.
Pompey were reduced to 10 men after 15 minutes as Dave Kitson floored defender Adam El-Abd, picking up a suspension his side can scarcely handle.
Things got worse after 25 minutes when Chris Wood gave his side the lead.
Ashley Barnes added a second from the spot on the stroke of half-time after Ibrahima Sonko handballed.
Liam Lawrence limped off in the second-half before Pompey pulled a goal back from sub Tom Kilbey - his first senior strike.
But Francisco Sandaza wrapped things up for the home side late on to give them a victory they thoroughly deserved.
To make matters worse, Pompey picked up seven bookings on top of Kitson's red card in an ill-disciplined display.