It took the old heads of Ryan Giggs and Michael Owen to overcome a spritely Southampton as Manchester United eventually progressed to the FA Cup fifth-round with a largely fortuitous 2-1 win. With United trailing at the break to Richard Chaplow's exceptional opener, Giggs came off the bench – as he did in midweek against Blackpool – to bring direction and composure. Not long after, United were level through Owen before Hernandez won it.
United started poorly and their defence continued to look shaky as the first half progressed, needlessly giving away possession and failing to deal with the home side's free-flowing game.
But for all the Southampton possession United looked dangerous when they were allowed time to break, and Gabriel Obertan should have done better with a drilled shot in the 33rd minute.
As the half came to a close, Southampton looked dangerous and were cursing Guly do Prado for putting a clear-cut header over. However, Chaplow atoned for his team-mate's miss moments later when the midfielder crashed home the opener from inside the penalty area.
The feel-good factor around St Mary's increased at the break as heroes from Southampton's victorious 1976 FA Cup side were paraded on the pitch.
Saints, then a second-tier side, famously defeated United that day and Ferguson was obviously keen to avoid another such upset. As United continued to struggle Ferguson called on the cavalry 13 minutes after the restart, bringing on Ryan Giggs and Nani in place of Darron Gibson and Anderson. The substitutions gave United the width they were crying out for and almost paid dividend immediately.
First a Giggs' free-kick resulted in Evans forcing Bialkowski into a save, before Owen flicked narrowly over from Nani's cross. Owen, though, soon found his range and drew United level in the 65th minute, nodding home Obertan's drilled cross.
Ten minutes later, with United eventually overpowering Southampton, the ball was worked through to Hernandez who squeezed the ball home for the winner.