With the top two inactive, third-placed Grimsby Town had the opportunity to cement their position and claw back some of the advantage that Cheltenham Town and Forest Green Rovers have over the Mariners.
And they managed a hard-fought 1-0 win against a still-not-safe Southport outfit at Blundell Park to move to within ten points of second-placed Forest Green with two games still in hand.
The 3,180 crowd had barely taken their seats when the Mariners scored what proved to be the only goal on a cold evening in Cleethorpes.
Padraig Amond scored his 27th goal of the after just a minute, bundling in the ball after Toto Nsiala's header had came back off a post.
Grimsby dominated possession but were unable to add to their tally, while Port`s best effort came when Steven Hewitt's effort forced home keeper James McKeown into an impressive save midway through the second half.
It`s as you were in fourth and fifth place as both Braintree Town and Tranmere Rovers were held to away draws by teams in the relegation battle.
Braintree were held to a goalless draw at Plainmoor by in-form Torquay United, whose four-game winning run came to an end, but they still managed to reduce the gap between them and fifth-bottom FC Halifax Town, who lost, to three points.
The home side`s Shaun Harrad went close to breaking the deadlock as did Toby Ajala.
The Gulls just about edged the game on the overall statistics, but couldn`t find that all-important goal.
Dan Lavercombe saved Mitch Brundle's effort late on, which was just about the Iron`s best opening of the game.
Tranmere twice had the lead at Nethermoor against Guiseley AFC but had to be content with a 2-2 draw.
Gary Brabin`s side went ahead after 35 minutes when home defender Rob Atkinson inadvertently turned the ball passed his own keeper.
But the lead lasted barely 3 minutes as Liam Dickinson volleyed home from six yards.
Just before the hour-mark, Rovers re-took the lead when Jake Kirby was on target.
But again, the Lions roared back to level within 2 minutes through James Hurst.
The draw leaves Guiseley five points above the drop zone.
The Kent derby between Dover Athletic and Welling United had significance at either end of the table.
But in the end, the hosts earned the spoils to move into sixth spot and to within three points of fifth-placed Tranmere with three games in hand.
Ex-Dover striker Michael Bakare gave relegation-threatened Wings a great start when he curled a beauty into the far corner of the net after less than 2 minutes had gone on the clock.
But on 23 minutes the Whites were back on level terms when Stefan Payne scored at the near post from a Ricky Miller cross.
However, Sean Raggett headed home from a Nicky Deverdics corner 5 minutes after the break to net what proved to be the winner.
Defeat leaves second-bottom Welling nine points adrift of the safety-mark.
Altrincham slipped further into that relegation scrap as they lost 3-2 against playh-off chasing Gateshead as the Robins completed a run of six successive home league fixtures, none of which they have won.
In fact, it is now just one win in their last hirteen league games.
Gateshead went ahead in the 11th minute when they broke upfield after an Alty attack had been ended by a foul by Josh O'Keefe. CJ Hamilton got up the left and his cross was converted by Danny Johnson.
Two minutes after the interval Altrincham were level when a Josh Ginnelly free-kick was whipped in and fumbled by Heed keeper Sam Russell. Marcus Holness arrived to bundle the loose ball home at the back post.
But, just 5 minutes later, a goalkeeping slip at the other end allowed Johnson to restore Gateshead's leak. His innocuous looking shot from the edge of the box seemed to skid on the soft surface past Tim Deasy's waiting hands and carried on into the net.
Alty went close, especially with a shot from Damian Reeves which fizzed past the wrong side of the post, but the visitors wrapped up the game, 5 minutes from the end of normal time.
Hamilton broke free up the inside left channel and finished impressively past the exposed Alty keeper.
Deep into added time Alty won a penalty for a foul on Reeves. Jake Moult's firmly struck spot-kick had enough power to get through Russell's hands to make it 2-3.
Then result leaves Alty in fourth-bottom spot, a point behind FC Halifax, while Gateshead are seventh, level on points with Dover.
Eastleigh are now two points behind Gateshead after coming back from behind to beat Woking 2-1 at the Silverlake Stadium in a game that saw both teams finish with ten-men.
The home side were dealt a massive blow when they went down to ten after just 19 minutes.
Paul Reid was shown a straight red card for an off-the-ball incident involving Mark Ricketts.
Six minutes later Woking took full advantage when Giuseppe Sole`s cross was headed home by Joe Jones.
On the hour-mark, however, the teams became even again when the Cards lost Kieran Murtagh to a second bookable offence.
Eight minutes later Eastleigh equalised, courtesy of Jai Reason's fine finish.
It looked as though it was going to finish honours` even, but 5 minutes into stoppage time, a Lee Cook cross was headed in at the far post by Will Evans to win it for Eastleigh.
FC Halifax Town are firmly back in the relegation dog-fight after losing 1-0 at mid-table Bromley.
What proved to be the only goal of the game came with 15 minutes remaining when Adam Cunnington converted Bradley Goldberg`s cross.
The Shaymen came close to equalising shortly afterwards, but Hamza Bencherif`s shot came back of a post.
Defeat saw FC Halifax drop a place to fifth-bottom, only a point above the relegation zone.
That was due to Boreham Wood`s battling point from their long midweek trek to Cumbria to take on Barrow AFC.
New loan signing Danny Haynes had a couple of chances for Wood, while home keeper Joel Dixon later saved well from Delano Sam-Yorke and Luke Howell.
Andy Cook came closest to a winner for Barrow, but his header from Jordan Williams' cross hit the bar.
Craziest result of the evening saw Chester FC hammer fellow mid-table side Aldershot Town 8-2!
The stats show that the home side scored with eight of their ten efforts on target!
James Alabi proved to be Chester`s hero, scoring four in the opening 45 minutes which saw the Shots turn round 6-1 down!
Sam Hughes and Ross Hannah both bagged braces for Chester, while Ross Laffayette and Dan Walker were on target for Aldershot.