Sam Osobe gave PNE a 1-0 lead at half time. In the second half Mlorcambe equalised before Danny Bircham game PNE a 2-1 lead. Further goals from Jordan Bent and Jack Ryan gave North End a 4-1 victory.
PNE now has 29 points from 13 matches and are two points ahead of Carlisle.
Carlisle won 4-1 at home to Stockport and have 27 points after 12 matches.
Burnley, who didn't have a match have dropped to third also with 27 points from 12 matches.
Tranmere are fouth with 24 points and Bury are fifth on 20 points, both have played 13 matches.