There was more drama at the death for City - but this time they were the ones smiling when the final whistle went.
The Bantams have already suffered late heartbreak twice in defeats on their travels this season, in the last minute at Morecambe and in the second minute of stoppage time at Barnet.
This time, the decisive goal came even later but for once it was at the right end for the 1,000-strong travelling City faithful.
The game had entered the fifth minute of stoppage time when Guylain Ndumbu-Nsungu coolly slotted past sub goalkeeper Gary Montgomery and the referee blew for full time the second the match restarted.
Some Bantams fans let their excitement get the better of them, spilling on to the pitch to celebrate the goal and it needed boss Stuart McCall to rush over and calm them down.
Such was the relief among supporters in a game it seemed City were destined to lose.
The bad omens started even before a ball had been kicked when Donovan Ricketts had to pull out of the squad on arrival after a stiff neck had worsened on the coach journey over to the east coast.
That left City without a substitute goalkeeper and, as sod's law would have it, on-loan stopper Rhys Evans had to come off after only 24 minutes with an injured left shoulder.
He had collided with former City striker Isaiah Rankin ten minutes earlier in claiming a difficult cross from Ciaran Toner. Mark Bower took the gloves and Matt Clarke filled in alongside David Wetherall.
Other than a smart snap shot from the edge of the box from Nsungu, the Mariners had been the better side up to that point.
Toner and full back Tom Newey were dominating down the left and Rankin and Martin Butler, on-loan from Walsall, were proving difficult to contain.
But Grimsby failed to test Bower before the break and City came more into the game, Barry Conlon's sliding effort going just wide and Eddie Johnson heading narrowly over.
It was a scrappy half but there were incidents aplenty after the break.
Things could not have started any worse for the visitors. On 48 minutes, Clarke opted to punt the ball long in the left-hand corner rather than pass back to Bower, who had come to the edge of his area for the ball.
But he mis-kicked straight to rightback Shaleum Logan, who lobbed the ball over the stranded Bower from outside the box with an accomplished finish to score despite the valiant attempt of Wetherall to clear on the line.
This stung City into life as Nsungu let fly with a wicked right-foot curler which Barnes did well to parry.
With the Congolese frontman dictating things, the Bantams went close through Kyle Nix, a Paul Heckingbottom free-kick and Nsungu himself again.
But then the action swung back to the other end.
Logan almost grabbed a second with a deflected effort, Nick Fenton hit the post with a header from a corner and Rankin saw a header go just the wrong side of the post.
Another goal at this stage and City were dead and buried, as Bower did well to palm over a free-kick from Newey. The makeshift keeper was growing into his role and came way off his line to claim the next corner.
With time running out, McCall's men thought they'd got the equaliser after 86 minutes when Nsungu got on the end of a Clarke flick-on from a long throw-in by Heckingbottom.
There looked to be nothing wrong with the goal but the referee spotted a push from the striker, though he appeared to show a yellow card to sub Luke Medley.
Man-in-the middle David Foster had kept a low profile up until this point but he was to make two more big calls as the game headed to a frenetic finish.
Medley chased down a long raking pass from Eddie Johnson, forcing keeper Barnes to come out of his area. He handled the ball and Foster - perhaps a touch harshly - stuck to the letter of the law and dismissed him for stopping a goalscoring opportunity.
It gave City added hope but they must have thought their chance had gone when Wetherall - who had just been booked along with Fenton after an altercation - put a header over the bar from close range with the goal at his mercy.
Step forward supersub Medley, who came off the bench to earn McCall his first win with a long-range beauty against Wrexham back in August.
He latched onto a ball into the box down the left and his pace forced a challenge from Whittle, which Foster ruled was illegal. Nsungu did the rest to gain what was a deserved point.
McCall admitted afterwards: "Because of the way things have been going over the past few weeks, I just thought we ain't scoring here'.
"So when it hit the back of the net and to hear the final whistle I was so relieved. As bad as I felt two weeks ago at Morecambe, it made up for it because it was such a relief."
That is not to say the City chief was altogether happy with a display, which was again patchy, particularly in the first half.
He said: "It took Rhys coming off for us to start the game. The first 20 minutes we were so lethargic.
"We'd emphasised during the week that they would be like we were against Darlington. They've been on a bad run themselves and were looking to start brightly and they did start the better side without doubt."
McCall added: "We need to be better than that if we want to go where we want to go.
"It was five out of ten but we kept at it and, with the circumstances, I think we merited a point with the chances we had."
TELEGRAPH & ARGUS
| GRIMSBY TOWN |