City were knocked out of the Carabao Cup at the first hurdle on Tuesday, slipping to a narrow 2-1 defeat at Rotherham United.
In an evenly-matched encounter it was the Millers who took the lead when Jamie Proctor fired past debutant Josh Vickers in the 36th minute but the Imps deservedly levelled 19 minutes into the second period with Billy Knott capitalising on a defensive slip.
The decisive winner came in the 78th minute when United pieced together arguably the best move of the game with substitute Anthony Forde providing the final touch to a Joe Mattock cross.
City boss Danny Cowley made four changes to his side for this Carabao Cup first round tie against Rotherham United at a very wet AESSEAL New York Stadium.
Coming in to the team were Josh Vickers, Billy Knott, Jordan Maguire-Drew and Harry Anderson with Paul Farman, Nathan Arnold and Matt Green dropping to the bench. Josh Ginnelly, meanwhile, was ruled out with an ankle injury sustained during Saturday's season opener at Wycombe Wanderers.
Heavy rain greeted the two teams as they were led out of the tunnel by referee Seb Stockbridge, with the hosts captained by a familiar face in the shape of Lee Frecklington. It was the Millers, via Frecklington, who kicked off.
City started brightly with Anderson fizzing a right-footed drive wide of the post after the opening five minutes were spent inside the Rotherham half whilst the hosts' first foray forward saw Frecklington have a cross blocked by Sean Raggett for a corner. Michael Bostwick rose high to clear the danger though.
In the 11th minute Rob Dickie was well positioned to block a Frecklington drive as the Millers started to get themselves into the game whilst at the other end Matt Green delayed a chip over the advancing Richard O'Donnell giving a covering defender the chance to deny him.
Rotherham's response saw them put together a quick counter-attack which ended with Vickers pulling off a fine save to tip behind a Kieffer Moore snap-shot whilst in the 17th minute home left-back Joe Mattock was booked for hacking down Green.
A meaty challenge on Jamie Proctor earned Raggett a 24th minute ticking off and three minutes later Moore curled a lame 25-yard effort well over the City bar. Bostwick then blocked a Frecklington drive for a United corner which came to nothing.
With the clock ticking into its 39th minute the Miller opened the scoring. Proctor was the man with the goal, the striker firing home from the 20 yards out having gained space before beating Vickers.
City's response was immediate with a deep Maguire-Drew corner finding the head of Raggett who was denied superbly by O'Donnell before referee Stockbridge awarded the home side a goal-kick, much to the annoyance of the Imps' players.
The half came to a conclusion following two additional minutes of play.
HT: ROTHERHAM 1 IMPS 0
Both sides emerged unchanged for the start of the second half so it was as you were as the Imps restarted proceedings.
City were quickly out of the traps with a dangerous Alex Woodyard cross causing problems for the Millers defence before referee Stockbridge halted a City attack to allow treatment to a grounded Rotherham player.
Five minutes in a low Anderson centre was cleared behind for City's second corner and when the ball was kept alive having initially been cleared Raggett saw his stooping header palmed behind by O'Donnell.
Appeals for a penalty as Green appeared to be pushed as he went up for a Maguire-Drew cross were then waved away whilst at the other end Vickers was forced to tip over a deflected Moore centre for a Millers corner.
Raggett picked up a 54th minute caution following a mistimed challenge on Moore and three minutes later a superb interception from Eardley saw him deny Frecklington as the former City man prepared to pull the trigger.
Vickers then saved from Ryan Williams as the Millers pressed for a second before the City debutant tipped over a goal-bound Michael Ihiekwe header at full stretch.
Both sides made a change in the 63rd minute with Anthony Forde replacing Ryan Williams for the home side whilst Ollie Palmer came on for Matt Green for the Imps.
Palmer's introduction paid immediate dividends as his first touch brought about a misunderstanding in the home defence between Semi Ajayi and his keeper O'Donnell and in nipped BILLY KNOTT to level matters in front of the 1,700 travelling fans.
Three minutes after the goal Nathan Arnold came on for Maguire-Drew and shortly afterwards Palmer was booked for questioning the assistant referee's decision to award Rotherham a throw-in despite Mattock clearly dribbling the ball straight out of play.
When the ball was switched to the other end Vickers tipped behind a dipping Newell drive and before the corner was taken Moore received attention after taking a knock.
The hosts kept pressing and with 12 minutes remaining they pieced together arguably the best move of the game which ended with Mattock crossing for substitute Forde to slot his side back in front.
Matt Rhead for Billy Knott was City's third and final change as the Imps prepared to take what turned out to be an unproductive 82nd minute corner. Three minutes later Anderson fizzed a right-footed drive a foot over the bar following good hold-up play by Arnold.
Jonson Clarke-Harris for Proctor was United's second substitution as the clock showed 87 minutes played and a minute later Palmer was denied by O'Donnell when a square ball to Rhead would have been a better option. Will Vaulks then replaced Lee Frecklington who received an excellent ovation from the travelling City fans.
City won a corner as the Fourth Official indicated a minimum of four added minutes but this was cleared and midway through the extra stages a push on Moore by Dickie gave United a free-kick 25 yards out which Forde curled wide.
This proved to be the last action with the Imps unlucky to be edged out of the competition by their League One hosts.
FT: ROTHERHAM 2 IMPS 1
21 Josh VICKERS
2 Sean LONG
10 Matt GREEN
11 Billy KNOTT
14 Jordan MAGUIRE-DREW
15 Rob DICKIE
16 Michael BOSTWICK
23 Neal EARDLEY
25 Sean RAGGETT
26 Harry ANDERSON
30 Alex WOODYARD
4 Elliott WHITEHOUSE
6 Callum HOWE
8 Ollie PALMER (for GREEN 63)
9 Matt RHEAD (for KNOTT 82)
12 Ellis CHAPMAN
28 Nathan ARNOLD (for MAGUIRE-DREW 67)
1 Paul FARMAN
GOAL: KNOTT (64)
BOOKINGS: RAGGETT (54), PALMER (70)
1 Richard O'DONNELL
2 Josh EMMANUEL
3 Joe MATTOCK
5 Semi AJAYI
8 Lee FRECKLINGTON
9 Jamie PROCTOR
16 Darren POTTER
20 Michael IHIEKWE
22 Joe NEWELL
23 Ryan WILLIAMS
24 Kieffer MOORE
4 Will VAULKS (for FRECKLINGTON 90)
7 Anthony FORDE (for WILLIAMS 63)
10 David BALL
11 Jon TAYLOR
18 Ben PURRINGTON
19 Jonson CLARKE-HARRIS (for PROCTOR 87)
30 Laurence BILBO
GOALS: PROCTOR (39), FORDE (78)
BOOKING: MATTOCK (17)
REFEREE: Seb Stockbridge
ASSISTANTS: Paul Thompson & Matthew Parry
FOURTH OFFICIAL: Ian Smedley
ATTENDANCE: 5,489 (1,706 City supporters)