The Aussie defender - who is younger brother of Shaun nodded a looping header of Lillywhites keeper Andy Lonergan as the visitors looked to take all three points.
Fantastic news for the Blades was that Carl Asaba and Robert Ullathorne played the full ninety-minutes as they should no sign of there recent injurys.
Wayne 'The Chief' Allison put the home side ahead before being substituted on hour mark. However strikes from Eric Skora and Kelvin Langmead gave Preston the lead before Murphy scored the leveler.
The Blades team included trialist Jarmaine Brown, the midfielder is from Arsenal and plays on the wing where he created some decent chances.
Sheffield United: Scott, Cas, Ullathorne, Thompson, Cryan, K.Murphy, Brown (Mallon 62), Tansley, Asaba, Allison (Killeen 62), Wood. Unused: Nugent, Baum, Purkiss.
Preston North End: Lonergan, Mears, Bailey, O'Neil, Kempton, McCormack, Anderson (Carvill 45), Rankine (Clampitt 65), Jackson (Onibuje 84), Langmead, Skora. Unused: Neal, Armstrong.