Southend United stretched their unbeaten run to 15 games by knocking League One Preston out of the FA Cup.
The Shrimpers nearly took the lead when Liam Dickinson's free-kick was fisted away by Preston's Thorsten Stuckmann.
North End responded through Paul Coutts, whose 25-yard shot was saved by Luke Daniels.
Dickinson broke the deadlock, volleying home from close range from Bilel Mohsni's header after Ryan Hall's shot was parried by Stuckmann.
Coutts had an effort ruled out for offside but the visitors could not find a way through despite a lot of pressure.
DID YOU KNOW?
Southend's last defeat was in September, the same month that Preston last won in excluding penalty shoot-outs
The first round replay defeat extended North End's wretched record to 12 games without a win in open play in all competitions.
And although the two teams play in different divisions, Preston sit just 10 places above Southend, whose excellent recent form has seen them rise to the top of League Two.
The Shrimpers will now host another League One side, Oldham Athletic, in the second round on 3 December.
VIEWS FROM THE DRESSING ROOMS.
Southend United manager Paul Sturrock told BBC Essex:
"The first half was pretty even, it was one of those scrappy games. I told the players at half-time we just had to lift it one gear, I thought that would be enough.
"We responded properly, got the goal, I thought we got sloppy again and decided to hang on - always a dangerous concoction that. I think we just shaded it."
Southend 31 Daniels 02 Clohessy 03 Gilbert 06 Bilel 12 Ferdinand 15 Phillips (Kalala - 81' ) 23 Barker 04 Hall Booked 08 Timlin Booked 09 Harris (Sturrock - 89' ) 22 Dickinson Booked Substitutes 01 Morris 05 Coughlan 16 Prosser 11 Sawyer 14 Johnson 19 Kalala 21 Sturrock Preston 01 Stuckmann 02 Gray (McLaughlin - 82' ) 05 Carlisle Booked 06 Morgan 08 Coutts 10 Nicholson Booked 15 Barton (Middleton - 71' ) 16 Mayor 17 Parry Booked 11 Tsoumou (Zibaka - 61' ) 33 Mellor Substitutes 43 Watson 03 McLaughlin 12 McLean 14 Smith 29 Middleton 36 Clark 40 Zibaka