John-Joe O’Toole’s early opener was cancelled out by Jason Demetriou’s penalty but Matt Grimes scored from the spot before Alex Revell’s late third lifted the Cobblers to within two points of safety as Southend suffered a sixth league defeat in seven.
The first half was short on quality and that was epitomised by Northampton’s opener in the 19th minute.
After Mark Oxley beat away Ash Taylor’s header, Harry Kyprianou’s attempted clearance cannoned off Matt Crooks and fell for O’Toole to guide the ball into the bottom corner.
The lead lasted just seven minutes, however, as Taylor collided with Stephen McLaughlin in the box and Demetriou slotted home the resulting spot-kick.
But the visitors were behind again early in the second half when Chris Long was fouled by Kyprianou for a penalty which was dispatched confidently by Grimes.
Cobblers debutant Hildeberto Pereira hit the crossbar moments after coming on before he set up the game-clinching third, slipping in Revell who found the bottom corner.
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Paris Saint-German have reportedly stepped up their efforts to sign Chelsea midfielder N'Golo Kante by speaking to his agent.
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Manchester City are hopeful a fresh offer of £7.5million in future add-ons will seal a deal this week for midfielder Jorginho.
Tite has described reports that he will take charge of Real Madrid after Brazil's World Cup bid as 'disrespectful and untrue'.
Newcastle United are reportedly lining up an audacious loan offer for Manchester United forward Marcus Rashford.
Ander Herrera will speak to interested clubs in January if Manchester United continue to leave his future up in the air.
Marko Arnautovic has dismissed rumours linking him with a move away, saying he has a contract with West Ham and is happy.