With the worst scoring record in the Premier League, Pompey fans were probably not expecting what was to come as their side ran riot at Fratton Park and booked their place in the quarter-finals of the competition.
Loanee striker Frederic Piquionne began the rout with a 17th minute header from a Nadir Belhadj cross although his best was mixed with his worst as he managed to miss scuff a few decent chances.
The Potters stayed with the home side for most of the remainder of the first half but their hard work cam unstuck ten minutes after the break when striker Danny Webber blasted home following a pass from Piquionne who was definitely very busy.
Four minutes later, Portsmouth went ahead 3-0, again through Piquionne who was on hand to tap-in after Stoke keeper Steve Simonsen was unable to hold on to a Michael Brown free-kick and the contest was rounded out when substitute Nwankwo Kanu received a pass from Aaron Mokoena, rounded Simonsen and slotted home in the 81st minute.