United left it very late on Sunday but Sophie Bell's calmly taken penalty, five minutes into injury-time, won the game and took the Bladettes into second in the league.
United started the day in third and visitors Radcliffe fourth, the two teams had cancelled each other out down in Nottinghamshire back in September with a rare, for United, 0-0 draw.
The home side were not at their best in the first half and unable to get into their usual passing style. They did have the better of the few chances, though, in the first quarter of the game, but Radcliffe restricted United to a few shots from outside the box. As the half wore on Radcliffe began to threaten more and after 23 minutes Beth Bailey fired the visitors ahead following pressure at a corner.
The visitors enjoyed their best spell of the game and hit the side netting on another attack. As the half came to its end the players and spectators had to cope with a blizzard replacing the earlier sunshine. It was just before the break United equalised when Millie Kenyon set up Nat Shaw to finish inside the box to send the teams in at 1-1 for half time and to get out of the wintry conditions.
United stepped up the pace almost straight from the restart and apart from when the visitors hit a United post, had the better of the second half by some distance. Striker Tania Marsden twice went close with headers as did Shaw, denied by former Blades goalkeeper Kirsty Johnson in the visitors goal. United were much improved and continued to carve out the better chances, Marsden was put through but fired just wide in perhaps the clearest chance of the game. United's veteran with over 100 goals to her credit went close twice more as United pressed.
Kim Brown, Shaw and a header from Rosa Neary all either went just wide or were saved as the game went into injury time. It began to look like time was running out to find a winner but there would be six minutes of added time after a collision between Marsden and 'keeper Johnson, which was United's first penalty shout.
Then, with five of the six minutes stoppage time played, a Bell ball into the box connected with a Radcliffe arm and the Blades were awarded a penalty. United were maybe a bit fortunate but some reward for all their perseverance. Bell stepped up to place the ball home for the dramatic winner.
Interim boss Carla Ward reflected: "It was a strange game, I felt we didn't get out of second gear. We had a few choice words at half time and I felt in the second half we looked a lot more like our ourselves but nothing seemed to be dropping. Credit to Radcliffe, they made it difficult but our girls fought to the end, never gave up and finally got our reward."
Blades: Houldsworth, Brown, Neary, Marshall, Barker, Bell, Hartley (Spurr), Pearson, Kenyon (Beanland), Marsden, Shaw.