The Blades had got through a bit ago after beating Darlington at the Feethams but had to wait upon this result to see as to whom they would face the the last four.
The Prenton Park club beat the Athletic quite convincingly with a 5-1 win. Alan Navarro, Paul Robinson, Ryan Taylor and Alex Hay put the home side into a 4-0 lead. David Martland pulled one back for the visitors but substitute Thomas Rooney wrapped things up late on.