Wyberton booked their place in round four of the Mason Bros Lincs Junior Cup - but manager Joe Greswell admitted his side were second best.
Curtis Revell netted a brace and Jamie Elston and Daniel White were also on target as the Colts twice came from behind to win at Spilsby Town, who had Josh Wood, Liam Papworth and Michael Twigg on the scoresheet.
“Spilsby where the better side, simple as that,” he conceded.
“For 70 minutes of the match they where better in every department. We are extremely lucky that we took our chances.
“Saying that, it’s been a long time since we have played that badly and won. I will take it though.”
Greswell gave the thumbs up to substitute Jon Macleod, whose impact helped Wyberton step up a level.
“Jon was the difference today,” the manager said. “Coming on at half time and changing the game.
“First half we were nowhere near them in the middle of the park. Jon came on and changed that, winning his first big tackle from the re-start and setting the tone of the second half.
“Spilsby can hold their heads high as they where the better side, not us.”
On a wet and windy day, the Boston League Premier Division highfliers started the better, but it was Revell who opened the scoring, firing home from inside the area.
The hosts fought back and took a 2-1 lead at the break.
The first goal came when Wyberton didn’t clear their lines from a corner, the ball put back into the box before a close-range finish levelled things up.
Spilsby’s second came from a similar position following a scramble.
After the break Wyberton levelled, Revell making no mistake from the penalty spot.
But it was Spilsby who took the lead again.
A corner was swung in deep and was knocked back into the danger area to be fired home.
But two goals in the final 15 minutes turned the game on its head.
Elston drew Wyberton level with a lovely curled shot from the edge of the area before White made sure the Colts progressed to the next round.
He picked up the ball outside the area and fired home to make it 4-3.
Wyberton travel to Cleethorpes Town Reserves for league action on Saturday (KO 2pm).