The Lions win in the corresponding fixture in October signalled the end of Terry Yorath's rein in charge at Hillsborough.
The Owls board were quick to appoint Chris Turner to revive the fortunes of the ailing South Yorkshire club.
However, while rivals and city neighbours United have gone onto bigger and better things, Wednesday's new boss has failed to influence things and his side lie rooted to the bottom with only seven games remaining.
Wednesday had only been beaten once on their travels this year and are at least making a fist of it and with Millwall's six defeats in the last eight games, they could not have picked a better time to visit South London.
Millwall manager Mark McGhee has been open in his criticism of his side's recent poor form, but a reported spat with Dennis Wise was dispelled as the midfielder returned to the side as captain.
A bright start by the home side went unrewarded and there was little sign of things to come as goalkeeper Tony Warner twice kept the visitors at bay.
A world-class save kept out Brian Barry-Murphy's header, and when Simon Donnelly crept in behind Darren Ward, the keeper was quickly off his line to block with a knee.
With half time fast approaching Millwall crafted a goal from nothing as Steven Reid thundered a half-volley into the top corner from the edge of the area.
The Republic of Ireland winger added another soon after as he reacted first to meet Steve Claridge's quickly taken free-kick, stabbing home at the second attempt after Kevin Pressman's initial save had rebounded kindly.
Wednesday would have felt hard done by at the break but some woeful defending nine minutes into the second half put the game beyond them as Danny Maddix merely set up Paul Ifill to thump home a third.
Even a consolation proved beyond Turner's men as Alan Quinn's shot came back off the post, and the Lions comfortably saw out the rest of the game despite the Owls manager's triple substitution with 35 minutes to go.