The former Hartlepool, Nottingham Forest and Bolton Wanderers midfielder scored the Gills’ final goal in a shock 3-1 win against the then top flight outfit with a majestic dipping shot at the Priestfield Stadium.
Wrexham v Maidstone United
The FA Cup
Second Round Proper
5.30pm, Saturday 6 December 2014
Racecourse Ground, Wrexham FC
Winners receive £27,000 from prize fund
Live on BBC Wales
And as the Maidstone United assistant boss prepares for his club’s Second Round tie with Wrexham this weekend, we invited him to take a look back at his memorable strike which sent the third-tier club into the last eight of the competition.
"I have watched it a couple of times, it's one of those iconic moments which you never forget as a player," Southall told FATV.
"I've dined out on that goal a few times now and the hairs on the back of my neck stand up just watching it now, the scenes were just incredible."
Middlesbrough-born Southall had four separate spells as a player with the Gills before leaving for the final time in 2012, but has settled in Kent and is now making his way in coaching with spells at non-League clubs Dover Athletic, Whitstable Town and the Stones.
But he admits that watching back the footage from that Fifth Round tie with the Owls makes him miss playing even more.
"It brings back everything you feel as a player," he added.
"Being on the side of management now, there's no better thing than crossing that white line and playing in front of the great support that we had that day for Gillingham."
Watch our feature with Nicky and footage of his goal against Sheffield Wednesday in the media player below.
Maidstone United assistant boss Nicky Southall relives his famous FA Cup strike for Gillingham.