First division Watford caused the upset of the day in this afternoon's FA Cup fifth round, beating Premiership strugglers Sunderland 1-0 to pile the misery on the Wearsiders.
The winning goal arrived courtesy of a twice-taken penalty by Tommy Smith at the Stadium of Light to leave the home fans calling for Howard Wilkinson's head.
The visitors were awarded a penalty in the 65th minute after Heidar Helguson became sandwiched between Jody Craddock and Michael Gray while contesting a cross and referee Mike Dean pointed to the spot.
Tommy Smith stepped up but drilled his shot straight down the middle of the goal and Thomas Sorensen saved with his legs, only for Dean to spot an encroachment by the Sunderland players and order a re-take.
Smith took on the responsibility once more and slotted home despite Sorensen almost getting a hand to it.
It was poor fare at the Stadium of Light with few chances created and the closest the home side came to scoring was Kevin Phillips' first-half 30-yard strike which went just wide.
Michael Proctor had a chance to snatch a replay deep into injury-time but from a difficult chance five yards out he could not shoot over the crossbar.
Southampton made no such mistake, reaching the quarter finals by destroying luckless Norwich with two late goals in a four-minute spell by Anders Svensson and substitute Jo Tessem - just after Paul McVeigh's fine effort struck a post for the visitors.
Norwich had covered themselves in glory with a gritty display after surviving Brett Ormerod's shot which hit a post in only the fourth minute but were gradually worn down by Saints' dogged persistence despite a string of impressive saves by Robert Green.
The visitors' anguish was complete when Malky Mackay was` sent off for a second yellow card right at the end.
Elsewhere, Sheffield United put themselves into the draw for the sixth round with a 2-0 win over Walsall.
They led 1-0 at half-time thanks to Tommy Mooney's goal but the highly-rated Michael Brown was the man who pulled all the strings.
It was Brown's shot which Saddlers' keeper James Walker could not hold and Mooney was on hand to stab home from close range. Brown was the creator for the second too as he wriggled his way into the left-hand side of the penalty area before crossing to the far post where former Coventry striker Peter Ndlovu headed home in the 56th minute.
Walsall then had manager Colin Lee sent from the dug-out for arguing with the linesman.
Earlier today, Manchester United were beaten 2-0 at Old Trafford by Premiership pacesetters Arsenal.