Goals from Sean Marks and Kenny Davis sealed victory for Braintree over Luton, who had new boss John Still watching from the stands.
Both sides were reduced to 10 men; the hosts seeing red first after Matthew Paine fouled Arnaud Mendy.
Wayne Thomas was then sent off after he was adjudged to have headbutted Marks.
Marks opened the scoring after slotting home from close range before Davis sealed victory with a headed effort from a Dan Holman cross.
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Braintree Town manager Alan Devonshire told BBC Essex:
"We've got another nine points to get (to avoid relegation). We've moved on well now, the last two games have been terrific, great performances by the boys.
"We're a young side. We've got a good shape about us now and everyone knows their jobs. It's took a bit of a while for some boys to settle in, but the last two results have been fantastic.
"They are playing with a lot of confidence and can't wait for the next game. I'm really looking forward to the end of the season now.
"We've worked hard on our fitness and it seems to have paid off. When you get tired, it ain't about your fitness levels, it's about how much heart you've got. I've got boys here with a lot of heart."