Both sides went into this midweek fixture having won on the opening day of the season and the first half was close, both teams almost cancelling each other out except for a rare lapse in the United defence which allowed Mansfield's Kokkinou to finish unmarked at the far post after 17 minutes.
United's best chance came shortly afterwards when Kim Brown`s shot forced Stags 'keeper Fenton into a good save. After that there was little to separate the teams and United went in at half time trailing to that soft goal.
The second half started much the same, both teams trying to play neat passing football on the floor. There were few real chances but plenty of effort and indeed no lack of passion with the scoreline so tight.
Boss Dan O'Hearne withdrew both his holding midfielders in a bid to find that equaliser. It almost arrived in a busy few moments when a Stags defender cleared off her own line and in the resulting melee United had a good penalty shout when Jodie Hartley appeared to be tripped.
The last 15 minutes was played almost entirely in the Stags half. Mansfield were defending so deep but surviving as injury-time arrive and then a deep cross from Sophie Bell had Stags 'keeper stretching and substitute Lucy Darbyshire took advantage to force the ball in from a yard out.
United celebrated as if they had won having never given up and were happy to come home with a well deserved point. It was also Darbyshire's first goal for United, already one more than in her 22 games last season.
United Manager Dan O`Hearne reflected: "We wasn't at our best and conceded a soft goal but we never gave up and got our deserved equaliser late in the game which tells me we have lots of belief and character within the squad."
Blades: K. Johnson, Cawthorn, Neary, Hartley, Spurr (Hickerman), Ruddach (Hall), Smith (Darbyshire), Pearson, Brown, Bell, Hopkinson. Unused: Wainwright.