The under-pressure boss saw his side grind out a narrow win at Deepdale courtesy of Paul Green's second goal in three games.
After quarter of an hour, Preston keeper Andy Lonergan punched away a free-kick by Kris Commons after Michael Hart had fouled Rob Hulse.
Roy Carroll saved a Neil Mellor 20-yard thunderbolt from inside the left channel after 22 minutes and he also held onto a left-wing corner by Preston captain Paul McKenna.
Derby's Przemysław Kazmierczak had a 12-yard right-foot shot from the centre of the penalty area which hit the post after a Commons cross.
Derby scored the winner after 40 minutes when a long left-wing cross from Jordan Stewart was met by Green and his looping header went over the keeper into the net.
Lonergan saved from a Green cross and then, just before half-time, Martin Albrechtsen fouled Darren Carter and Ross Wallace drilled a 20-yard free-kick from the left channel which was saved by Carroll.
Early in the second half, Carroll saved again from Chris Sedgwick and the Preston keeper made a save from Commons.
Stewart had a cross caught and then Sean St Ledger had a 12-yard header from the centre of the penalty area saved following a free-kick by Wallace.
Rob Hulse had two efforts saved and Wallace had another cross caught by the Derby keeper.
Preston substitute Simon Whaley had a late cross-shot saved by man-of-the-match Carroll.