The Blades had goalkeeper Paul Rachubka to thank who allowed James Beattie long ranger tame effort slip under his arms into the back on the net in the 89th minute as the former Evertonian cancelled out Blackpool's strikes to level the score at 2-2.
With the game drawn near to a close the visitors looked out of the game and were heading to their third straight successive away defeat this season - in fact you have to go back to 16 December 2006 when a single Rob Hulse goal beat Wigan Athletic 1-0, that was the last time the Blades have won away from Bramall Lane.
United did play some good football at times and there best came early on when striker Jonathan Stead provided some tantalising touchers
And, on the 12th minute a spectacular cross to the far post was met by the familiar head of James Beattie who added to his goals tally.
The Seasiders keeper had to make a fantastic save to prevent Shaun Barker from turning into his own net whilst at the other end Paddy Kenny did the same to stop Gary Naysmith's badly timed header to stop a goal from being scored.
As the game went on the home side improved with David Fox terrorising the centre of midfield whilst Wes Hoolahan dominated the wings.
With half-time looming the home side struck abundance and hit United hard; Andy Morrell was brought down at the edge of the box with Stephen Crainey taking the free-kick. The former Leeds United man turned home a stunning drive past Kenny to level the scores.
The home side had their chances to seal the victory in the second half but Gary Taylor-Fletcher and Wes Hoolahan were both thwarted by keeper Paddy Kenny.
They did however take the lead on 87th minute who's Andy Welsh cross was met by the glancing head of Ben Burgess after lovely play by Hoolahan - the home side thought they had won the game but James Beattie was to add a twist into this game when two minutes later his long range shot crept under the keeper and into the goal.
Sheffield United move down three places to 11th in the table whilst Blackpool also slip down to eighth after starting in last play-off spot. The Blades have just 8 points after six matches played and will be looking to shoot up the table when they play Crystal Palace at Selhurst Park next Saturday.