Mansfield and Grimsby were forced to share the spoils in a hard-fought encounter at One Call Stadium.
Grimsby enjoyed the better of the exchanges in the first-half and Mansfield were much improved in the second period.
Boss Nigel Clough made one change from Saturday’s 1-1 draw at Stockport as forward Rhys Oates replaced Kieran Wallace in the lineup.
Inside the opening minute, Grimsby tried to set a front-foot tempo as Andy Smith hit a speculative effort which goalkeeper Christy Pym comfortably gathered at his near post.
And the Stags’ shot-stopper was called upon more significantly two minutes later when John McAtee got the better of Riley Harbottle to advance one-on-one with Pym, but the Peterborough loanee got down low to his left to make an excellent stop.
Grimsby continued to threaten and Stags were fortunate to see Niall Maher’s ball flash across the face of their goal, with no-one in a black and white shirt able to connect.
Stags began to get a foothold in the game and crosses into the box from Elliott Hewitt and Hiram Boateng, from right and left respectively, attempted to send a warning shot across the Mariners’ bows.
Grimsby though were soon causing problems, this time from corners.
First, a flag-kick into the goal mouth spun off the boots of Lucas Akins and similarly off Mariners’ defender Luke Waterfall as he attempted to line up a cleaner effort.
The towering centre-half had an even better chance from the subsequent corner moments later when he powered a header goalwards, which Pym superbly stopped on his goalline.
The all-action start continued and Keillor-Dunn did well to find Akins 20 yards from goal, who – after controlling smartly - lashed a strike narrowly over the bar.
On 20 minutes, Stags were relieved to see the ball clip back off the woodwork after McAtee’s deep cross deceived everyone.
Three minutes later, Akins showed fine strength to hold off his marker before squaring it to Boateng who lashed over from 22 yards and soon after, Keillor-Dunn cracked a 27 yard free-kick off target.
On 35 minutes, Keillor-Dunn displayed fine skill to sweep a dangerous cross from the right flank, but a pack of advancing players were unable to meet it inside the goal area.
Grimsby then missed three golden chances to take the lead, all within a heart’s beat.
Andy Smith broke the offside trap, only for Riley Harbottle to make a superb last-ditch challenge near the penalty spot as Smith was set to pull the trigger. McAtee then followed up with a shot which spun into the path of Waterfall. But the defender couldn’t make the most of a glorious chance and blasted wide from the edge of the six-yard box.
Eight minutes after the restart, referee Tom Reeves brandished the game’s first yellow card when Niall Maher hacked down a darting Rhys Oates outside the box.
And from the resulting 22-yard free-kick, Boating’s curler cannoned off Waterfall to spin behind for a corner.
Stags upped the ante and Oates did well to find Akins who turned 10 yards from goal to see his shot immediately blocked, before Hewitt sent a 20-yard piledriver over the angle.
Second-half chances were at a premium but Jordan Bowery managed to force Max Crocombe into a diving save after a mazy run down the left saw him cut inside and fire towards the far corner of the goal.
In a rare second period attempt for the Mariners, substitute Harry Clifton fired a low drive wide and then at the other end Rhys Oates watched as his effort clipped a Grimsby defender to trickle behind for a corner.
With 82 minutes played, both sides made a double change. For Mansfield, forward Danny Johnson and the versatile Jason Law replaced James Perch and Hiram Boateng.
Keillor-Dunn and Johnson both had half attempts sail off target in the dying minutes, before the referee blew for full-time.
STAGS: Pym, Hewitt, Harbottle, Kilgour, Perch (Johnson 83, Bowery, Clarke, Boateng (Law 83), Keillor-Dunn, Oates, Akins
UNUSED SUBS: Flinders, Anderson, Wauchope, Wallace, Gale
GRIMSBY: Crocombe, Emmanuel, Waterfall, Smith, Maher, Glennon, Holohan, Morris, McAtee (O’Neill 82), Lloyd (Khan 82), Taylor (Clifton 70)
UNUSED SUBS: Efete, Hunt, Orsi, Khouri
REFEREE: Tom Reeves
ATTENDANCE: 7,569 (1,102 Grimsby supporters)