A quality start from Forest enabled them to go ahead in the first 90 seconds without Preston even touching the ball.
A flowing move using all the pitch finally found Charlotte Hartley in the attacking quarter, who slipped it past the goalkeeper.
Forest were dominant and thought they had gone further ahead when Hartley was unmarked at the top of the D, only to see her shot rebound off the underside of the crossbar.
Again Forest pressured into the attacking zone and a Preston foot on the line gave an opportunity for Lisa Crewe to make it 2-0 with a penalty flick. Crewe secured the flick and two minutes later went on to fire the ball across the goalkeeper, finding the bottom left corner.
Forest seemed to be able to split Preston and find all the gaps. Accurate passing then found Karen Wignall, who, with great timing, tucked the ball past the goalkeeper and Forest were 4-0 up.
After the break, Forest were goal hungry, and Hartley managed a second when a one-two with Crewe was neatly placed past the keeper.
Forest dominated possession, but chances were flying by. Hartley could have had a hat-trick but for the frame of the goal - hitting the crossbar again from a deflected shot.
Amazingly Forest managed to hit the frame of the goal seven times, with Hartley, Thea Cormack and Crewe also hitting the post.
They had to settle for a 6-0 win when the final goal came from Wignall who slid in on the end of a cross and deflected the ball into the corner.
They are now officially league champions with three games to go, and play South Lakes at home tomorrow, at 11-30 a.m. at Marsden Heights.
In the Lancashire Central Women’s League Premier Division, Pendle Forest seconds took on Lancaster.
Forest started off dominating play, moving the ball well against tough opposition. Pendle penetrated Lancaster’s defence in the first 10 minutes, with a strike from Alison DeCurtis lifting the ball into the back of the net.
Pendle kept up the pressure and added a goal from Zoe Kidney.
Just before half-time, Pendle scored again from a goal in open play from Natalie Mitchell, going in at half-time 3-1 up.
Lancaster came out strong in the second half, but Forest’s defence stayed strong to finish 3-1 winners.