A LAST-gasp equaliser from substitute Dayle Southwell extended Grimsby Town’s unbeaten run to 11 games.
In a scrappy game, Joe Healy’s early strike looked like it would be enough to seal all three points for the visitors.
After breaking the deadlock, Welling then looked to defend their advantage as a below-par Town struggled to find a way through and extend their excellent run of form.
As the game went on, frustration began to set in both on and off the pitch as the away side looked like they were going to hold on for their second single-goal victory over Grimsby of the season.
But the Mariners stuck to their task right to the very end and they got their reward when Southwell prodded home to level the scores deep into injury time and snatch a point.
Manager Paul Hurst named an unchanged Town starting line-up after Saturday’s FA Cup victory over Northampton Town.
That meant it was James McKeown in goal, with Sam Hatton, Shaun Pearson, Clayton McDonald and Aswad Thomas forming the defence.
Alex Rodman started on the right side of midfield, with Scott Kerr and Craig Disley in the middle and Scott Neilson on the left.
Ross Hannah and Lenell John-Lewis were the strikers, with Joe Colbeck, Andy Cook, Paul Bignot, Dayle Southwell and Paddy McLaughlin all named as substitutes.
The Mariners were looking to reclaim fourth place in the Skrill Premier on their return to league action after three consecutive cup games.
But their visitors were out to complete a double after winning the reverse fixture in August.
Lone striker Ross Lafayette would be out to cause problems for the home defence.
Hannah won an early free kick and Kerr tried to send Thomas through with a low ball but it proved to have just too much pace on it and was watched out for a goal kick by right-back Dereece Vanderhyde.
Disley then fired over the bar from 12 yards after Thomas had crossed from the left as the hosts looked for an early breakthrough.
Hannah was brought down midway inside the Welling half on nine minutes but Kerr’s free kick was wasted, as he sent the ball out for a goal kick.
The opening goal came on 11 minutes and it was the away side who went in front with their first real chance of the game. Town failed to clear a cross from Kurtis Guthrie on the right and HEALY was there to send the ball past McKeown and into the net.
At the other end, John-Lewis created an opening before the ball broke for Rodman but a good challenge from Blaine Hudson meant keeper Lee Butcher was not called into action.
Jake Gallagher was dispossessed by Hannah in midfield on 19 minutes and the striker let fly with a shot from long range but his low effort did not trouble Butcher as it rolled wide.
A free kick to the Mariners came when John-Lewis was fouled by Guthrie on the left three minutes later and Kerr’s looping delivery was headed down by Disley but it stayed out of the net and Butcher punched the rebound away for a corner.
A good run down the right from Rodman led to a cross going into the Welling box but nobody was there to meet it and Vanderhyde headed clear.
Guthrie was shown the game’s first yellow card for a bad foul on Thomas on the Town left but Pearson was penalised for holding onto his man when Kerr’s ball came over from near the corner flag.
Another cross came in from Hannah on the right after a mistake by keeper Butcher but again, nobody in black and white could get on the end of it.
Lafayette was bundled over by McDonald, who was booked for the foul inside his own half. Alex Dyer’s resulting free kick caused no problems for McKeown.
A good Town move involving John-Lewis, Neilson and Disley led to a corner on the left on 33 minutes and Pearson’s header from it was deflected behind for another flag-kick, which led to Healy clearing off the line.
Defender Fraser Franks was penalised for a foul on Hannah four minutes before the break but Hatton’s free kick from 25 yards hit the Welling wall.
The game was becoming scrappy, with several fouls giving it a stop-start nature as frustration began to set in among the Town players and supporters.
Guthrie escaped a second booking for a foul on Thomas inside the Grimsby half just before the game moved into two minutes of added time.
The Welling winger was involved again soon afterwards but this time, he was the man being fouled as Kerr picked up a yellow card.
A deep cross from McDonald was comfortably claimed by Butcher in what was the last meaningful action of the half, meaning the visitors went in with the advantage at half-time.
No changes were made before the restart and a foul by Jake Gallagher earned him a booking four minutes in. Town looked to try a set-piece from the free kick but it did not lead to a chance in front of goal.
After an uncertain start to the half, the home side began to control possession and territory, albeit without testing Butcher in the Welling goal.
A Baily Cargill cross from the left was put behind for a corner by Pearson on 57 minutes but McKeown came off his line to punch player-manager Jamie Day’s kick clear, before Hudson headed at the keeper when the ball was crossed back into the box from the right.
The first substitution of the night saw Guthrie replaced by Aristide Bassele just before the hour, before good skill from Neilson saw him race into the box from the left but his shot was blocked, as was Hannah’s rebound.
A similar run from Rodman led to him hitting a shot that was deflected out for a corner, which was sent in low for Hannah to hit a snap-shot that was blocked on the line.
Neilson made way for Colbeck as Town boss Hurst made his first change, before Cook was sent on in place of John-Lewis with 25 minutes left to play.
Grimsby won a corner on the left on 70 minutes but again, it caused no serious problems for Butcher as Kerr’s kick was headed away at the near post before the return ball was caught by the keeper.
Rodman fired a shot from 25 yards after being found by Thomas on the left but the effort was comfortable for Butcher, who stooped to gather the ball.
Dyer pulled a shot wide for Welling after a pass from Day, before Town had their best chance yet when a driven free kick from Hatton looked to have got a touch from Cook as it hit the inside of the far post but rolled back across the goal-line where it was touched wide.
Southwell was sent on for McDonald as the Mariners opted for an extra striker in a bid to salvage something from the game.
McKeown’s evening had been a relatively quiet one in the Town goal but he was called upon to keep his side in the game with a superb double save from Lafayette, blocking the first shot with his feet before pushing away the rebound.
Hannah hit a right-footed shot wide with two minutes to go as the home side continued to look for an equaliser.
Colbeck upended Lafayette to earn the latest booking as four added minutes were signalled by the fourth official.
Town kept attacking in search of that elusive leveller and it finally came when a long throw from Hatton was flicked on and SOUTHWELL was there to prod the ball into the net from close range.
That proved to be the last real action of the game and the Mariners will now look ahead to Saturday’s FA Trophy trip to Barnet.