It is the best run of form since the days of Brian Clough – and it was also a special day for manager Billy Davies, as he masterminded an emphatic win over his former club.
Three points were also enough to lift Forest back up to third in the Championship table, level on points with second placed West Brom.
The first goal came as Paul McKenna chose a fitting time to net his first for the club since signing from Preston over the summer. The Forest skipper produced a spectacular strike, sending a dipping shot accurately inside the post after a corner had been half cleared to the edge of the box in the 16th minute.
Just under ten minutes later it was 2-0, as Forest attacked with purpose again from another flag kick, with Nicky Shorey this time firing the ball back into the box after it had been cleared to the left flank – and Dele Adebola providing a simple, but emphatic finish from close range.
Richard Chaplow's driven shot into the side netting represented Preston's only meaningful effort of the first half hour, as Forest maintained almost relentless pressure.
Paul Anderson was only denied by a fine save from Andy Lonergan after he had been sent racing clear, while Raddy Majewski sent a superb bending effort inches wide of the post with the keeper beaten.
Preston kept things rather tighter after the break and, after making a double change with strikers Neil Mellor and Jon Parkin coming off the bench, Mellor missed a good chance with almost his first touch of the game, firing over from ten yards.
McKenna had clearly also found his range after finding the net in the first half, connecting with another spectacular long range effort that flashed across goal and narrowly wide.
Although Ross Wallace also came close to pulling one back for the visitors as he lashed a crisply struck left foot shot just wide of the target as Lee Camp looked on.
Earnshaw was denied yet again as a clever exchange between he and Chris Cohen sent him racing clear, only for Lonergan to save brilliantly at his feet.
It seemed a little ambitious when sub Garath McCleary tried his luck on the run from more than 25 yards, but Lonergan had to make a good save to pounce on his skimming shot.
The keeper was helpless to deny Forest their third however, as he again saved well to thwart substitute Lewis McGugan, only for the midfielder to prod home the rebound through the unlucky keeper's legs in the 82nd minute.