Jay Bothroyd fired Cardiff joint top of the npower Championship as Portsmouth were swept aside 2-0 at Fratton Park.
Bothroyd forced an own goal from Hayden Mullins before the interval and doubled the lead early in the second half thanks to some more calamitous Pompey defending.
These two sides met in the FA Cup final little more than two years ago but are heading in different directions these days. Pompey, who won that Wembley encounter, are still in administration and could name just four substitutes again while Cardiff, with loan signing Craig Bellamy running the show, are dreaming of the Barclays Premier League.
Cardiff went ahead eight minutes before the break after Marc Wilson uncharacteristically lost possession in the middle of the park.
Chris Burke scampered clear and crossed into the area where the ball found its way into the net off the shin of Mullins, under pressure from Bothroyd.
They were gifted the goal by another mix-up in the Pompey defence which left Bothroyd with an open net to tuck away his sixth goal of the season in the 49th minute.