Quincy Owusu-Abeyie stepped off the bench to fire Portsmouth into the FA Cup quarter-finals after a thrilling clash with Southampton at St Mary's.

The Pompey substitute was introduced to a pulsating end-to-end encounter shortly before the hour mark and broke the deadlock in the 66th minute with a classy finish before having a hand in two of his side's further goals.

Southampton, who did not look like a side who ply their trade two divisions below their fierce South Coast rivals, hit back almost immediately with top scorer Rickie Lambert heading home from close range.

But former Arsenal and Birmingham forward Owusu-Abeyie, who is with the financially-stricken Fratton Park club on loan from Spartak Moscow, then set up Aruna Dindane with a slide-rule pass in the 75th minute.

Alan Pardew's battling side pressed to get back on terms for a second time, leaving inevitable holes in defence which Avram Grant's troops were only too happy to exploit.

The outstanding Jamie O'Hara showed his class to release Nadir Belhadj to make it 3-1 with eight minutes to go and the on-loan Spurs midfielder then smashed in a fourth after Belhadj and Owusu-Abeyie combined.

Reaching the last eight of the FA Cup gives Pompey a rare glimmer of hope in a season which sees them rooted to the foot of the Premier League table and on the brink of financial meltdown.