After Norwich's 2-1 win against Nottingham Forest last night, the Bluebirds went into the encounter knowing they needed three points to lift themselves back into the top two.
And they secured just that thanks, in the main, to a fluent attacking display full of endeavour.
That intent was epitomised by Craig Bellamy, who began a scintillating performance by setting up Seyi Olofinjana's opener.
Pompey's cause was then hampered when Ricardo Rocha received an 18th-minute red card.
The Bluebirds capitalised on their one-man advantage with goals from Jay Bothroyd and Peter Whittingham capping an excellent effort.