Grimsby Town were forced to settle for a draw as Walsall came from behind to share the points at Blundell Park.
The Mariners took an early lead through James Hanson and were the better side for much of the first half against one of their relegation rivals.
But on a frustrating afternoon, they were unable to add to their advantage and were pegged back in first-half stoppage time when Caolan Lavery equalised.
A win would have brought Town to within six points of their visitors in the battle to stay in League Two but despite no lack of effort, they could not find a breakthrough in the second half.
Grimsby boss Paul Hurst made just one change to his starting XI after Tuesday's victory at Barrow, as Giles Coke replaced Danny Rose in midfield.
James McKeown started in goal with Luke Hendrie, Elliott Hewitt, Rollin Menayese and Harry Clifton forming the defence, as Coke slotted in alongside Jay Matete and Luke Spokes in midfield and Lenell John-Lewis, Hanson and Stefan Payne again formed a three-man attack.
Luke Waterfall returned to the bench after missing the midweek trip to Cumbria through illness and he was joined among the substitutes by Ollie Battersby, Ira Jackson Jr, George Williams, Matt Green, Rose and Julien Lamy.
Walsall arrived in Cleethorpes on an 11-game winless run which had seen them slip closer to trouble at the bottom end of the table.
They would look to forwards Lavery, Josh Gordon and Emmanuel Osadebe to provide the firepower to ensure the nine-point gap between themselves and the Mariners was not closed further.
An early stoppage came after a heavy challenge from Payne on Walsall's James Clarke and when the game restarted with the defender passed fit to continue, the visitors had two opportunities to get the ball into the danger zone from free kicks but both were dealt with by the Town defence.
At the other end, the Mariners took the lead on eight minutes with their first real attack of the game. A cross from Hendrie was headed towards goal by Payne and after his attempt was kept out by keeper Liam Roberts, HANSON followed up to find the net from the rebound.
Payne was shown the first yellow card of the game after a foul on Osadebe, before a foul by Spokes on the Walsall right gave the away side another free kick. Again, they were unable to take advantage though.
Hendrie won a free kick when he was fouled on the Town right on 15 minutes but Spokes' delivery was eventually put out for a throw-in after nobody could make contact with the ball in the penalty area.
Matete was hurt in a challenge on the halfway line on 22 minutes but played on after receiving treatment, then a shot from Stuart Sinclair was blocked by Spokes and an effort from distance by Osadebe was tipped over the bar by McKeown for a corner.
From the flag-kick, Matete was in the right place to clear a header from Tom Leak off the line, then Lavery was unable to connect with a header after the ball was worked back and crossed from the right.
Matete went down again soon afterwards and this time, had to come off. Rose was sent on in his place.
Shots from Hanson and Coke were blocked in quick succession as Town aimed to double their advantage, then an effort from Payne on 35 minutes was pushed away by the keeper after good work by Hanson.
Osadebe saw a shot blocked at the other end, before John-Lewis slipped as he looked to shoot on the turn after a good through-ball from Spokes.
A foul on Coke by Lavery gave Town a free kick inside the Walsall half on 42 minutes but Spokes' ball from it was too close to Roberts and he claimed a comfortable catch.
Five added minutes were played at the end of the half and in the first of them, the away side struck back as they grabbed an equaliser. Gordon found the space to cross from the left and his ball picked out LAVERY, who flicked a header past McKeown for 1-1.
The hosts had been the better side throughout the half and would have deserved to lead at half-time but Walsall had shown enough to suggest that one goal may not be enough and so it proved, with the sides going in level at the break.
Callum Cockerill-Mollett replaced left-back Max Melbourne for the visitors before the restart and a Walsall corner three minutes in eventually led to Lavery prodding a shot off-target.
Payne won a Town corner at the other end but Spokes' ball from the flag was headed clear at the near post.
A foul on Lavery gave the away side a free kick on the right on 55 minutes but the ball from it was cleared by Menayese, then a foul on Payne brought a Grimsby free kick but Rose's delivery failed to beat the first defender.
Lavery won another free kick after turning past Coke on the hour but the visitors could not take advantage as Osadebe's ball was flicked away from goal.
At the other end, a cross from Hewitt had too much power for Hanson to connect with at the end of a mini spell of Town pressure which had also seen blocked shots from Coke and Clifton.
A header across goal from Hanson was cleared after good link-up play between Clifton and Rose down the left but the Mariners were unable to keep the pressure going as a cross from Hendrie on the right sailed out of play for a goal kick.
Williams replaced Spokes and Jackson came on for John-Lewis as Town made a double-substitution on 73 minutes, with the game in the balance.
Payne flicked a header wide from a left-wing cross by Clifton on 79 minutes, before Menayese conceded a corner but the ball from the flag was cleared.
Lavery fired over the bar after Liam Kinsella had done well to cut in and pull the ball back from the right with six minutes to go.
The away side kept attacking and Osadebe landed a free kick on thee roof of the net from wide on the left.
A foul on Williams at the other end gave Town a free kick on 89 minutes but the midfielder's shot from it bounced back off the Walsall wall.
A Mariners corner followed soon afterwards but nobody in black and white could turn Williams' ball towards goal.
Two added minutes were played at the end of the game, with Town desperate to find a winning goal to give their survival bid extra momentum.
But that priceless goal was not to come and in the end, both sides had to settle for a point.
It means the Mariners are now unbeaten in six games, although they may look on this match as an opportunity missed to make further ground in the battle to avoid relegation to the National League.
Town are next in action on Good Friday, when they travel to Salford City.
1 James McKeown
2 Luke Hendrie
15 Harry Clifton
26 Rollin Menayese
22 Elliott Hewitt
20 Jay Matete
8 Giles Coke
14 Luke Spokes
9 James Hanson
21 Lenell John-Lewis (C)
40 Stefan Payne
13 Ollie Battersby
6 Luke Waterfall
4 Danny Rose
10 George Williams
7 Matt Green
16 Ira Jackson Jr
42 Julien Lamy
1 Liam Roberts
18 Tom Leak
3 Max Melbourne
5 James Clarke (C)
4 Mat Sadler
7 Stuart Sinclair
8 Liam Kinsella
20 Sam Perry
9 Caolan Lavery
10 Josh Gordon
23 Emmanuel Osadebe
13 Jack Rose
14 Callum Cockerill-Mollett
2 Cameron Norman
12 Alfie Bates
15 Wesley McDonald
11 Derick Osei Yaw
27 Tyreik Wright
Referee: Samuel Barrott
Next Up: Salford City (A)