A Danny Mills strike was enough to give Tamworth victory over 10-man Braintree and help them leapfrog their opponents.
Mills fired home from the edge of the penalty area after picking up Paul Green's pass.
Andrew Yiadom and Chibuzor Chilaka both missed chances as Braintree looked for an equaliser.
The away side's evening was made worse just before the final whistle when Kenny Davis was sent off for a foul on Liam McDonald.
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Braintree Town manager Alan Devonshire told BBC Essex:
"Adam (Bailey-Dennis) has got in a tackle, I think the fellow left a foot in, caught him on the back of the head.
"He's lying on the floor and their 23 (Iyseden Christie) has come over 20 yards with his fist in his face.
"Kenny Davis has then run over and pulled his arm away, that was it. So why has 23 got booked and Kenny Davis has got sent off? It's ridiculous."