Braintree overcame struggling Nuneaton in an enthralling six-goal thriller.
James Mulley nodded the Iron ahead, but Boro levelled when Simon Forsdick headed home Adam Walker's corner.
Dan Holman's strike from 18 yards restored the visitors' advantage shortly after the break before Dean Wells' superb free-kick made it 3-1.
The hosts set up a tense finish when Delroy Gordon powered home a header from close range but substitute Bradley Dack struck to secure Braintree's win.
VIEW FROM THE DRESSING ROOM
Braintree Town assistant manager Keith Rowland told BBC Essex:
"I think it was as good a performance as we've had all season. To go away from home in the Conference and score four goals.
"Really I don't think the home team have got many complaints. We defended pretty well, we were comfortable for long periods.
"The goals came at really good times for us, like they have to when you are away from home.
"Dean Wells' strike (from 60 yards) was magnificent for this level of football. To have the intelligence to see it and to hit the ball with such quality was worth the admission money."