It had seemed supporters were in for some rare excitement with a penalty shotout - there is no extra-time in the early stages of the competition - but Mirfin had other ideas. Not that the Iron fans were complaining.
The opening half was dull. Joe Murphy, the home keeper, tipped a long-range effort from Will Buckley and Sam Togwell fired over the crossbar for the Iron.
Paul Hayes saw a low shot saved by Sam Russell, a former Iron loanee, early in the second-half as the game threatened to turn into something entertaining.
Unfortunately it did not, and it was not until the final stages when the supporters who braved the fog had anything to get excited about.
Lee Thorpe, on as a substitute for the visitors, forced Murphy into two great saves - his only real action of note in the game - to keep the score goalless.
Moments later Mirfin forced the ball home to avoid a penalty shootout, although Chris Dagnall almost levelled for the visitors with a shot that went narrowly wide of a post.