Goals from former Glover Lawson D’Ath and striker Marc Richards was enough to secure the three points for The Cobblers.
Manager Paul Sturrock made three changes from the starting eleven that lost to Wycombe Wanderers on Tuesday evening.
Matty Dolan, Francois Zoko and Ryan Bird dropped to bench to be replaced by George Thomas, Ryan Dickson and Josh Sheehan. New loan signing Christian Maghoma started his life as a Glover with a place on the bench.
Town started the game brightly and had the first chance of the match when Cornick got in behind the Northampton defence only for his touch to be a bit heavy and goalkeeper Adam Smith managed to gather the ball just inside the area.
On 15 minutes the home side could have opened the scoring when striker Marc Richards headed straight at Weale when he probably should have done better when he had most of the goal to aim at.
Five minutes later Thomas took the ball of the left boot of Dickson just inside the area. Wirth the skipper ready to give Thomas a talking to, the Coventry loanee turned his marker to curl just wide of the far post.
With Yeovil having their best spell of the game the home side took the lead with ten minutes of the first half remaining.
From a Dickson corner the home side cleared and broke away quickly. The ball found its way to former Glover D’Ath who made no mistake in rounding Weale to slot home into the empty net.
The second half began with both sides struggling to get their foot the ball with the wind playing a big part in both team struggling with their passing.
The home side doubled their lead with just over ten minutes of the second half played. A cross from the right from Nicky Adams was met by captain Richards, who made no mistake in slotting home from close range.
On 63 minutes a corner from the right was swung in by Dickson onto the head of Cornick, but his header bounced back off the bar and the home side managed to clear away.
Despite the wind at their backs and slippery conditions the Glovers failed to test Smith in the Northampton goal and returned home empty handed.