Crawley ended Newport County's 18-month unbeaten home record to reach the FA Cup first round draw.
The Blue Square Bet Premier rivals produced few chances between them before Craig McAllister settled the clash with a fine effort.
Scott Neilson provided the final pass for striker McAllister to deliver the winner with a single touch.
That 77th-minute strike was enough to send the Welsh club out in the fourth qualifying round.
Crawley manager Steve Evans told BBC Sussex: "It could have been three or four today for us.
"It was as good and professional a performance as we've had all season. We conducted ourselves in the most professional manner, which we expert at Crawley.
"Because of our financial situation we are now the biggest scalp."
Bookmark with:
What are these?