Northampton captain Kelvin Langmead grabbed a late winner to earn his side victory against 10-man Southend.
The Cobblers went ahead when Roy O'Donovan hooked the ball home following a long throw from Ben Tozer.
Bilel Mohsni, who was making his first appearance for Southend in nine months, was sent off after 27 minutes for a foul on Chris Hackett, but the 10 men equalised through Matty Lund's header.
However, Langmead's close-range header on 90 minutes secured all three points.
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Cobblers boss Aidy Boothroyd tells BBC Radio Northampton:
"I thought overall we deserved it. Paul Sturrock will probably feel his team could have won it as well.
"When you go down to 10 men, all of a sudden, your team seems to get extra energy from somewhere, and the team with 11 seem to think they're all right and drop down a gear.
"Roy O'Donovan is getting better and better with every training session. His goal today was top drawer.
"Kelvin Langmead is as brave as a lion. That's why he's the captain. He's been brilliant. I'm lucky to have him."