Todd Jordan replaced the injured Jon Nolan in midfield for this Skrill Premier game against Gateshead at Gelder Group Sincil Bank Stadium whilst there was a welcome return on the bench for Danny Rowe, back in the fold following a lengthy spell out through injury.
Gateshead kicked off attacking the Stacey West Stand and enjoyed some early possession, although play was concentrated in their own half during the first few minutes.
It was City, though, who created the first chance at goal when a long Tom Miller throw-in was diverted off Nat brown's head by a defender but Alan Power's resultant corner sailed over everyone and out for a goal-kick.
City remained on the offensive with Power winning another corner in the 10th minute and when Sean Newton's dangerous inswinger was headed clear, Jake Sheridan was felled 25 yards from goal. Newton was duly denied by a good Adam Bartlett save though.
Gateshead's response saw them swarm forward in attack but Paul Farman pulled off a great save to deny Walker who found himself one-on-one with the stopper after John Oster spotted him in space with a cross from the right. Farman required treatment before play resumed after getting in the block in a delicate area.
A surging run forward by centre-back Luke Foster brought about a third City corner shortly after the quarter-hour mark; this saw Power pick out Brown but he was penalised for a push before getting in his header.
A mistimed challenge by Power on Craig Baxter earned the City skipper a 21st minute booking - and with it being his fifth of the campaign a ban will be heading his way as a result.
The next half-chance saw Jordan slice a shot wide from just inside the box whilst at the other end Gateshead's first corner was headed away by Brown at full stretch.
A quiet spell ensued with chances at a premium but things livened up in the 40th minute when Sheridan escaped a caution after catching Baxter as he closed down his clearance. Baxter then went in hard on Power as temperatures started to heat up.
A Miller throw-in then ended with visiting skipper Ben Clark grounded and in need of attention after taking a blow to the face. A drop-ball in the Gateshead box was the outcome with the visitors duly humping it out for a throw-in.
The half ended after three additional minutes and with Clark still off the field receiving attention.
HT: Imps 0 Gateshead 0
Clark failed to emerge for the start of the second half with his replacement being Liam Hatch. With Hatch coming on up front, Carl Magnay slotted in alongside James Curtis in the centre of defence.
The Imps were the first to threaten following the break with a trip on Sheridan by Phil Turnbull bringing about a free-kick which saw City keep possession in the attacking third before referee Amy Fearn awarded a goal-kick, despite the ball clipping a visiting defender before going out of play.
A second Gateshead substitution came along nine minutes in with Marcus Maddison replacing Jamie Chandler and a couple of minutes later the 31 visiting supporters were on their feet when Walker slotted into the bottom corner of Farman's net from the edge of box after Oster opened up the Imps' defence with a run down the right.
Nine minutes later City had a lucky escape when Mo Fofana appeared to bundle Maddison to the deck in the box. Referee Fearn waved play on, much to the annoyance of the Gateshead players, before stopping play when Farman launched his drop-kick forward with the substitute grounded.
City's first switch saw Nick Wright come on for Chris Sharp in a straight swap up front as the game approached its final quarter. Magnay then went in hard on Jackson giving the Imps a free-kick which was taken by Power and easily claimed by Bartlett.
A foul on Brown earned Maddison a 72nd minute caution whilst a minute later Miller joined him following a block on Hatch. At the other end a free-kick to the Imps saw the Gateshead players surround referee Fearn again and once she waved them away, Newton's delivery clipped a blue shirted player before going out for a throw-in on the opposite flank. This throw led to a corner which was headed over by Foster.
Sheridan became the latest recipient of a yellow card after catching Baxter before Power fired over from a City attack. A long Miller throw then ended up with the ball bouncing into Bartlet's gloves.
With seven minutes on the clock Maddison went in with a high boot on Brown leaving referee Fearn with the easy option of giving out a second yellow and a red for the Gateshead substitute.
Bohan Dixon replaced Mo Fofana for the final five minutes whilst Joe Tait for James Marwood was Gateshead's last change; the latter taking some time to be completed before Wright's appeals for a penalty after he went to ground fell on deaf ears.
Four additional minutes was indicated by the Fourth Official and these were dominated by Gateshead whose possession saw them through to the maximum points.
FT: Imps 0 Gateshead 1