An injury time goal from Bruno Andrade decided the contest as Northampton Town were beaten 3-2 by Lincoln City.
Northampton had come back into the contest from 2 goals down against the League 2 leaders. The home side had taken a 2 goal lead through goals from Harry Anderson and Tom Pett.
But the visitors saw Jack Bridge pull a goal back moments after Lincoln went 2-0 up, before a late Kevin van Veen goal looked to have forced a replay.
However, late on, Andrade struck to decide the game, while Northampton also had Junior Morias sent off late on after an off-the-ball incident.
The result means a First Round exit for the Cobblers, although there were promising signs after they fought back against a side who have made a positive start in League 2.
Northampton fell behind after 16 minutes, when a flying cross from the Lincoln City left flank picked out Anderson in the middle, and the Lincoln man rifled home.
Shay McCartan saw a fine drive saved by David Cornell and another go wide, while Northampton’s best first half chance saw a long range John-Joe O’Toole blasted strike repelled by Josh Vickers.
Lincoln made it 2-0 just after half-time, as Pett raced on to a loose ball just outside the penalty box and perfectly placed a first-time drive beyond Cornell.
But Northampton weren’t 2-0 down for long, as Bridge hit a low first-time shot into the bottom corner, despite Vickers getting a touch.
It was van Veen who then bought Northampton level in the final 10 minutes of the contest, with a firm strike into the roof of the net as he collected a cross from the right.
The match looked as though it was heading for a replay. But Lincoln then had a winning touch, as Andrade fired a 25 yard curling drive beyond Cornell.
Morias was then dismissed in the 9th minute of added time, as Northampton suffered a First Round exit for the second straight campaign.