Barnstaple Town will face Toolstation Western League First Division rivals Almondsbury UWE if they make it through their FA Carlsberg Vase replay against Newquay.
A trip to Bristol in the first round is the prize awaiting the sides in tomorrow night's clash at Mill Road.
Saturday's original second round qualifying tie ended in a 2-2 draw in Cornwall. Barnstaple scored twice late on through Jed Harper-Penman and Ryan Turner to come back from 2-0 down and force extra time against their South West Peninsula League hosts.
Almondsbury, who beat Radstock Town 1-0 on Saturday, will host the winners on Saturday, October 19.
While Barnstaple are in second place in the First Division with an unbeaten record from seven games, Almondsbury sit 11th with four wins and five defeats. The sides are due to meet in the league at Mill Road two weeks after the Vase tie.