Romford boss Steve Butterworth called his side 'superb' after their FA Cup giantkilling of Potters Bar Town.
Boro fell behind after 18 minutes of the second qualifying round tie as Jacques Kpohomouh struck for the Isthmian League Premier Division hosts.
But Charlie Morris levelled with a header from Kris Newby's corner and Town were reduced to 10 men early in the second half when Boro old boy Tyler Christian-Law was sent off.
Emmanuel Robe came off the bench to net a 77th-minute winner to delight the visiting fans and Butterworth said: "We were superb. The game plan was mastered very well.
"We sat back, let them dictate. We knew they were big and strong and forced them to play the opposite, give them the ball and teams then tend to try and pass it.
"We played on the break and once the red card happened I fancied us. We got the subs on, some fresh legs, and looked like scoring every time we went forward.
"We could've had more. They put us under pressure towards the end but the two centre-halves were unbelievable. The group was immaculate.
"We were up for it. We're not really a step five side, they've all come from higher, we're more a decent step four side. We've done well."
Having now picked up £8,194 in prize money, following earlier wins over Saffron Walden Town, Takeley and Hashtag United, Boro were handed a home tie against National League South side Chelmsford City in Tuesday's draw.
And that October 1 fixture, where winners collect £5,625 and losers £1,875, has left supporters excited after the two clubs enjoyed some great battles in the old Southern League days, with some calling for the tie to be televised by the BBC!
Butterworth added: "It's a good draw for the club, Chelmsford being a derby from back in the day.
"We should get our best home crowd of the year and can go the same [as Potters Bar] and anything is a bonus. It's a banana skin for them.
"At this stage the worst you can get is a National League South side away and we've got one at home. They're flying. We know we won't win the FA Cup, so lets just enjoy it.
"Even when I was playing step three and four I don't think I got to the first round. You've got to win five or six games and beat sides from two or three leagues above.
"Enfield are probably our closest rivals and got battered by Billericay, who are struggling.
"It's so hard not to get ahead of ourselves, when you're getting text messages from people. There's no given at the minute. We've got to enjoy it."
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