Wilkin lobbed the keeper Mark Samways after 26 seconds to provide the midfielder Darren Harmon with a simple header and scored the fourth goal himself with the last kick. Northampton, beaten 7-0 at Scunthorpe in October, struggled to improve on their bright opening and had to wait until the second half to make their mark again with two goals in five minutes through Terry Fleming (penalty, 65) and the substitute Martin Aldridge (70).
Peterborough are in deeper trouble near the bottom of the First Division following a 3-2 defeat at Grimsby - the Mariners' first home win since New Year's Day. Posh took a surprise ninth-minute lead when Tony Adcock took advantage of a Paul Agnew slip to slot the ball past Paul Crichton.
Paul Groves equalised with a header (45) and Grimsby took the lead when Steve Livingstone, back after a three-match ban, scored a fine individual effort (58). Gary Childs then shot home (68), only for Dominic Iorfa (72) to give Posh hope.