Former Northampton defender Daryl Burgess had a nightmare return to his old club as the Cobblers romped to a third straight victory in Coca Cola League Two.
Burgess diverted an eighth minute cross from Lee Williamson past his startled goalkeeper Neil Edwards who set the ball rolling for the home side.
And twelve minutes later Burgess was shown the red card by referee Joe Ross after tripping Eric Sabin as he bore down on goal. Martin Smith tucked away the penalty kick to leave the visitors with an impossible task.
Smith, last season's top scorer for the Cobblers, grabbed his second of the game after 28 minutes with a brilliant left-foot shot on the turn into the far corner.
But he spurned a glorious chance to complete a hat-trick three minutes later. After being played into the box by a brilliant pass from Tommy Jaszczun he fired wide with the goal at his mercy.
Scott McGleish almost made it 4-0 in the 57th minute when he cut in from the left before teeing up a curling shot which cracked the visitors crossbar.
And the flow of one-way traffic continued two minutes later as Edwards saved smartly from Joshua Low 's header.
The home side finally extended their lead in the 63rd minute when a Low cross had Edwards at full stretch and his attempted clearance went in off a post.
But the visitors showed some spirit to reduce the arrears with 14 minutes left. A corner by substitute Leo Bertos was bundled in by Gareth Griffiths after a goalmouth scramble.
Edwards made a fine reflex save to tip a Pedj Bojic drive over the bar with 10 minutes left and Low twice went close before finally getting his name on the score sheet for the first time this season when his injury time drive from the edge of the box was deflected past Edwards.