Nine men held on for three points as Spalding United slipped into the play-off pack.
Conor Marshall and Jonny Lockie were both dismissed in the second half at the Sir Halley Stewart Field on Tuesday night.
But the Tulips took the honours thanks to goals by former Lincoln United pair Nathan Whitehead and Gary King.
Rob Norris pulled one back and Spalding were hanging on pretty desperately for the final 15 minutes following Lockie’s red card.
Michael Duggan pulled off a series of saves to show yet again why he was voted the number one in this division last season.
He had little to do during the first half – but he was kept very busy after the break.
The Whites must have gone away wondering how they had lost considering all the late pressure.
Duggan denied ex-Tulips Jack McGovern, Jack Wightwick and Ryan Oliver while Norris hit the base of the post and more attempts missed the target.
Spalding survived penalty appeals for handball against Whitehead as well during a spell when they were forced back.
The defence hardly got outside the penalty box and the midfield had no options other than smashing the ball to safety into the other half of the pitch.
To their credit, Spalding’s nine men showed spirit and character to claim the derby victory.
Those qualities had been questioned after two heavy defeats over the August bank holiday weekend.
But they have bounced back to get into the promotion frame even at this early stage of the season, getting close to an average of two points per game.
Let’s remember they got into the play-offs last term despite ‘nightmare November’ which produced one point from five matches!
A lack of discipline must be the biggest concern right now, though, as three players are facing suspensions.
Matt Varley’s sending-off on Saturday was followed by a similar challenge on Tuesday when Marshall lunged into Norris. The referee reached into his back pocket and got out the red card.
He had to do the same all over again just 14 minutes later, clearly indicating that Lockie had used an elbow to get rid of Callum Ward.
Norris had reduced the deficit against 10 men, poking home from close range and giving Duggan no chance after Wightwick’s burst into the box.
But Spalding held on to the advantage which began when Varley’s long throw was not cleared and Whitehead hooked the ball beyond Jake Turner.
In the fifth home game of the season, that was Spalding’s first goal in ‘open play’ rather than directly from a set-piece.
Whitehead’s pass set up King to double the lead with a shot which deflected off Lincoln captain Phil Watt inside the near post. And that proved just enough in the end.
4-4-2: Duggan 8; Fixter 7, Spafford 7, Humble 7, Jackson 7; Marshall 4, Whitehead 7, Varley 7, Acar 7 (sub McGhee 83 mins); Reittie 6 (sub Lemon 63 mins, 7), King 7 (sub Lockie 65 mins). Subs not used: Townrow, Fletcher.
4-2-3-1: Turner; Ward, Watt, Blunden (sub Wightwick 32 mins), Matthews (sub Cann 78 mins); Toyne, Brooks (sub Oliver 60 mins); Millard, Norris, Cotton; McGovern. Subs not used: Foster, McGann.
Whitehead (11 mins, 1-0); King (54 mins, 2-0); Norris (74 mins, 2-1).
Marshall (serious foul play); Lockie (violent conduct).
Varley, Acar, Watt (fouls); Toyne (dive).
Michael Duggan – series of saves to keep maximum points.
Leek Town (A) – Saturday.