Stunning goals from Lee Novak and Levi Sutton, his first for the club, will live long in the memory but the way they gritted their teeth in the second half was even more important as they held firm after Harry Clifton's goal and claimed a 2-1 win.
The Bantams were hoping to have Stuart McCall's replacement in place by the time of last night's game but the way caretaker managers Mark Trueman and Conor Sellars, they might even be pleased they took their time. In a week-and-a-half they have coaxed seven points from a possible nine from a group of players who were only out of the League Two relegation zone on goal difference when they started.
You do not attempt shots like Novak and Sutton's unless you have confidence on your side, and the duo appear to have very quickly instilled that.
By the same token, dump-in-the-dumps teams, which is what City were three games ago, do not usually hold firm after giving the home side a route back into the game at the start of the second half, as they did on a cold night on the east coast.
The Mariners were much the better side in the opening 20 minutes, but the Bantams stuck to the way they have been asked to play and grew into the game. An overhead kick from Novak certainly helped them along the way.
City were visited by a few ghosts of Christmases past in the opening minutes, Paudie O'Connor blocking a shot from former Bantam Kyle Bennett, and Luke Hendrie shooting at Richard O'Donnell after being fed by Filipe Morais.
Luke Spokes also volleyed wide at a corner, Montel Gibson headed over from another.
Anthony O'Connor had to read the game well to pick out potentially dangerous balls from Ira Jackson and Bennett.
Bradford, though, continued to try to get the ball down and play football more colourful than their ghostly grey away strip, making some committed tackles to get it back when they lost it, as exemplified by Sutton.
They had barely threatened the Grimsby goal in the 22nd minute, but Novak's goal was more than worth the wait. When Callum Cooke played the ball in from wide, he chested it and cleared James McKeown with an overhead kick.
A frustrated spectator in the final weeks under McCall, who brought him to Valley Parade after working with him at Scunthorpe United, Clayton Donaldson has been kept on the bench since the club legends' departure, with room for only one striker in the stand-ins' 4-2-3-1 formation.
Novak has scored two goals in three matches. It is an important statistic because when he scores, City do not lose.
From there, they slowly took a grasp on the half.
Sutton had a shot deflected for a corner as they built pressure and whilst Billy Clarke's cross was cut out, the way he teed it up with a flick showed the side's growing self-belief.
Their football was not gung-ho, though, O'Donnell resisting the temptation to hammer the ball downfield out of his hands, instead picking out Clarke on the right touchline. He in turn played a measured pass Sutton lobbed over McKeown in the 43rd minute.
Clifton's goal, three minutes after the break, was a panic-spreader.
Bennett was afforded too much space and Owura Edwards, one of two half-time substitutes as Ian Holloway changed his strikers, touched the ball back for Clifton to neatly and efficiently find the net.
Inevitably, much of the second half was played in City territory but the Mariners had little to show for it – a Luke Waterfall header over at a corner and Spokes's wild shot from distance the exception rather than the rule. Tigerish tackling, like the way Connor Wood and Elliott Watt denied Hendrie.
When Bradford were able to counter Clarke shot at McKeown after being forced wide, Callum Cooke missed the target after strong work by Harry Pritchard and was brilliantly denied by the goalkeeper. The way substitute Kurtis Guthrie beat his man and crossed with the outside of the boot would have made it a goal worthy of sitting alongside Novak and Sutton's but City were not going to do things the easy way, which made victory even sweeter.
Grimsby Town: McKeown; Hendrie, Waterfall, Hewitt, Preston; Morais (Starbuck 84), Spokes (Rose 84), Clifton, Bennett (Tilley 64); Jackson (Edwards 46), Gibson (Green 46).
Unused substitutes: Russell, Idehen.
Bradford City: O’Donnell, Cousin-Dawson, A O’Connor, P O’Connor, Wood; Watt, Sutton; Clarke (Guthrie 69), Cooke (French 90), Pritchard (Evans 69); Novak (Donaldson 82).
Unused substitutes: Samuels, Longridge, Hornby.
Referee: J Busby (Oxfordshire).
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