Cheltenham Town substitute Kayode Odejayi scored with virtually the last touch of the game three minutes into injury time to give manager John Ward a victory over his old club.
Ward was born in Lincoln and played for the club for many years but there was no sentiment in his thoughts after the game as Cheltenham Town made it five wins in their last seven games.
Play-off chasing Lincoln, who had to make four changes due to injuries, a suspension and the departure of left-back Paul Mayo to Watford, were also hampered by the sending off of Richard Liburd for two bookings on the half-hour mark.
Lincoln had made the perfect start to the game by taking the lead after only three minutes, Marcus Richardson latching onto a poor defensive header by John Brough and rolling a shot in off goalkeeper Shane Higgs.
Cheltenham hit back and created a number of chances before Grant McCann, in front of the watching Northern Ireland boss Lawrie Sanchez, curled a wonderful free-kick from a tight angle to the right of the penalty area in off the far post.
The free-kick was awarded for a handball which earned Liburd his first booking. The second arrived three minutes before the break when he made a late challenge on Tony Griffin.
Despite this setback Lincoln took the lead again when the rangy Richardson won himself a penalty in first half injury time. Richardson converted the kick himself to make it 2-1.
The goal arrived against the run of play as Cheltenham had dominated the first half. They did not play anything like as well in the second period against 10 men but still managed to grab two late goals to clinch the points.
The first was driven in by former Lincoln player John Finnigan from the edge of the area after a corner had been headed out to him, and the second was a looping header by Odejayi from a Martin Devaney cross.
Cheltenham manager John Ward said: "This was a fantastic win for us against a very good side. I think it is a reward for the way we have stuck together during the last few weeks. We were lacking a bit of quality in the second half and in the last 10 minutes we launched the ball into the box and a couple of things fell for us." Lincoln boss Keith Alexander talked of trying to strengthen his side ahead of their next game: "I'm disappointed with the result but I'm not going to criticise the players. We had to make four changes and had a man sent off but we battled well and I thought we would get something from it.
"I will try and get a couple of new bodies in for the next game."