Goals in each half from Louise Fors and Katrin Omarsdottir saw the Reds crowned champions for the first time in their history on a nerve-shredding final weekend of the season.
Matt Beard's side, who started the day two points clear of their closest rivals, needed only to draw to clinch the championship but secured a convincing victory at Halton Stadium.
Liverpool had enjoyed prolonged pressure but it took a spot-kick to make the breakthrough, Swedish star Fors converting from 12 yards after Nicole Rolser was felled.
Natasha Dowie spurned a fine chance when she headed wide on 71 but Omarsdottir finally killed off the contest seven minutes later, jinking her way through blue shirts before finishing with ease.
The triumph marks a stunning turnaround in fortunes for Liverpool, who had finished bottom of the table for the past two seasons and won only one game during the 2012 campaign.
But, following huge investment from the club's American owners, the Reds won 12 of 14 fixtures this season to herald a changing of the guard in the women's game.