With United, who were second in the table, having two games in hand on Wednesday in third, many on the red half of the Steel City believed their return the Championship to be a foregone conclusion - so much so they were particularly vocal about it on Twitter.
A week later, the two sides met at Hillsborough, in a closely fought derby encounter which United could seemingly afford to lose. And lose they did, with Chris O'Grady's second-half header enough to seal the win for the Owls in what proved, somewhat bizarrely, to be Gary Megson's final game in charge.
Dave Jones replaced him in the S6 dugout and won 10 of his 12 matches as the Blades capitulated, allowing their neighbours to snatch the final automatic promotion spot on the very last day of the campaign.
Fast forward to now and Wednesday are mounting another assault on promotion, this time to the Premier League, while United languish ninth in League One after three failed attempts at the play-offs.
And Owls fans are not about to forget it, taking to Twitter themselves to retweet the best of those premature posts:
sheffield united win, wednesday lose, 5 points clear with 2 games in hand ..go on son! #SUFC— Jordan Lamb (@jordanlamb94) February 18, 2012
5 points clear of sheff weds and 2 games in hand :) #sheffutd— Becky Castledine (@beckyklie) February 18, 2012
Just thought we could go 5 points clear today with 2 games in hand, beat them 8 points win 2 games in hand 14 points? THIS CITY IS OURS #UTB— Harrison (@NorthernHarry) February 18, 2012