Third Division top dogs Hartlepool battled back after a shaky start to tighten their grip on the leadership and send Lincoln to their first defeat in five games.
Two goals in three second-half minutes put paid to brace City in an entertaining game.
There was an early shock for the home team when Lincoln took the lead with just over a minute gone with a goal scored by a player who spent a handful of games on loan with the club from Stockport six years ago.
Stuart Bimson curled a right-wing corner to the near post where Adie Mike towered above everybody to head powerfully into the roof of the net.
Pool spent the rest of the first half on the attack, but with top scorer Gordon Watson starting his spell on the sidelines after breaking his leg at the weekend, they struggled to create chances.
Their best was a header from Watson's replacement, Adam Boyd, that skimmed the bar and a great shot on the turn by Eifion Williams that was well saved by Alan Marriott.
It looked like being the same story in the second half, but those two quickfire goals shook City and sent another big crowd home happy.
Pool had had two strong penalty appeals waved aside before they drew level on 62 minutes, and the hero was Watson's replacement Boyd.
The local youngster scored with a stunning overhead kick after Chris Westwood headed the ball back into the box following a corner.
And three minutes later Lincoln were on their knees as star man Richie Humphreys burst into the box and appeared to be fouled, but before anybody could complain Williams seized on the loose ball and hammered a low shot into the bottom corner for his third goal in four days.
Pool had to battle to hold on as Lincoln tried to fight back themselves, but the home side deserved to hold on for a breathless victory.
Lincoln boss Keith Alexander said: "I'm very disappointed for the players, they've done exceptionally well against a side that looks good enough to win the League.
"They put us under a lot of pressure, but we made them work hard and I'm proud of the team."
Hartlepool manager Chris Turner said: "It was good to see the way we were patient and fought back after being behind from the first minute.
"We knew Lincoln wouldn't make it easy for us, and they proved us right."