Forest top scorer and Wales striker Robert Earnshaw had an early chance after eight minutes when he fired a 20-yard right-foot shot straight at the Preston keeper Andy Lonergan.
Preston bounced back when their captain Paul McKenna hit a 25-yard right-foot shot from inside the left channel which was saved by Forest keeper Paul Smith.
Ex-England striker Andy Cole was making his first start for Forest and hit a 12-yard right-foot shot from the right side of the penalty area which the Preston keeper saved.
In the 31st minute Neil Mellor had a 25-yard right-foot shot from inside the left channel caught by Smith and a minute later Darren Carter, who was replacing the injured Championship player of the month Richard Chaplow, had a 25-yard left-foot shot tipped over the bar by Smith for a left-wing corner.
Lonergan also tipped over a Chris Cohen 20-yard shot from inside the left channel just before half-time.
Preston made it 1-0 in the 49th minute when a Carter left-foot right-wing corner was headed into the bottom left of the net from 12 yards by Youl Mawene.
Soon after Preston made it 2-0 when Neil Mellor got his fourth goal of the season, a header into the bottom left of the goal from six yards out after a right-wing cross and assist by Barry Nicholson.
Mellor had another effort moments later from 18 yards which was saved by Smith and Jon Parkin, his fellow striker, had an 18-yard left-foot shot from a central area saved by the keeper.
Guy Moussi brought a save from the Preston keeper with a 20-yard effort and Carter hit an 18-yard drive which was caught by Smith.
Lee Martin hit over a cross after 67 minutes and Mawene headed it into his the bottom left corner of his own net to make the score 2-1.
Substitute Matt Thornhill had a 20-yard left-foot shot from inside the right channel which was saved by the Preston keeper with nine minutes to go.