United had won the reverse fixture 4-2, with the Bantams having two players sent off in that fixture, but it was both sides on the end of the referee's discilnary proceedings on this occasion, with Scunthorpe completing the domestic double over the side.
Oliver Lobley restored parity in the game, after the away side had taken the lead, while Joey Dawson completed the turnaround to net the winner before Cameron Wilson was one of two players shown a red card by the match official. It was an eventful afternoon for the Scunthorpe number 12, who provided both of the assists for the goals before his afternoon ended prematurely.
Professional Phase Development Coach Steve Thornber said: "It was similar to last week really in that we didn't start the game too well and found it difficult to come to terms with their shape.
"We changed our shape slightly at half-time and played much better in the second half. We were very positive and we dominated large periods of the game. We got in some good positions throughout the game. The passing and link-up play was very good and we just needed to be a little bit better in the final third."
The game's first chance fell the Iron's way after three minutes when the home side were awarded a free-kick on the left side. Wilson curled the ball into a dangerous area, but the ball went wide of the far post and out for a goal kick.
The visitors had a couple of early chances of their own, but goalkeeper Jake Balme was alert to hang onto his clean sheet, making a couple of routine saves.
On 20 minutes, Patrick Virgo was played through by Lobley before being denied by the visiting shot stopper.
Eight minutes later, the Bantams goalkeeper was called into action once more as Wilson whipped in a cross which was met by the head of Oliver Kemp, but again the ball stayed out of the back of the net.
On the half-hour mark, Dawson found space on the edge of the box to cut onto his left foot, with his left-footed effort seemingly destined to nestle into the bottom corner, but for a superb save from the 'keeper, with the ball tipped around the post.
Three minutes later, following a couple of Iron corners, Bradford broke to take the lead. A cross came into the box, with the Bantams making first contact to send the ball into the next.
United immediately pressed for an equaliser, with Virgo coming closest to restoring parity as he cut inside on his left foot before firing wide.
Despite a largely dominant second half performance, Balme had to be at his best in the Scunthorpe goal to prevent Bradford from doubling their lead five minutes into the second half. A curling effort needed to be tipped over and that's just what he did.
A minute later, Kemp was able to stride out from the back before having a go from 40-yards. The effort took a deflection and the visiting goalkeeper made the save.
On 55 minutes, United pressed once more, with Lobley having an effort from the edge of the area parried out for a corner.
United were piling on the pressure for the equaliser and kept breaking the lines and playing down the channels, but the side couldn't find the killer cross.
On 63 minutes, Cribb dispossessed in midfield and fed into Dawson before the ball was worked out wide to Baker. His cross was only half-punched clear by the 'keeper with Wilson connecting with a low half-volley into the corner which was just about prevented from going over the line. United kept the ball with Lobley on the left before Moore, Gallimore and Baker interchanged on the right. The latter crossed before the ball was teed up for Wilson, who curled a left-footed effort just over the bar.
Dawson then went close as he found space in the area to send his own left-footed shot just wide of the target.
That equaliser did come on 65 minutes and it was more than deserved. Gallimore's persistence saw him charge down an attempted clearance from the visitors, with the ball ricocheting to Dawson. He played the ball back to Gallimore on the right before he cut back to Wilson. He then drove into the area on the right side before looping in a cross which was on a plate for Lobley to head home the equaliser from a yard out.
Ten minutes later, it was Bradford who pushed forward to try to go ahead, with Balme again making a save as he tipped over a shot from the edge of the area.
The match winner came 12 minutes from time in the 78th minute when United won the ball back on the nearside touchline. Virgo kept the ball in play before beating his man and playing in Wilson down the right channel. He brought the ball forward before playing the ball across the box. The Bantams couldn't clear, with Dawson pouncing on the loose ball to slot home from close range.
Virtually from the restart came the game's big talking point. United broke forward again, with Virgo pulling up just outside the penalty area. The game was swiftly halted for treatment for the Iron player, but frustrations flared as the Bradford City goalkeeper got involved to try and hurry things up, which led to players from both teams clashing.
Wilson and a Bantams outfield player were brandished straight red cards by the referee, while Joey Dawson and two Bradford players all saw yellow in the aftermath.
With both teams down to 10 men, United remained on top, with a number of tackles flying in in the final few moments, with Dawson having the final effort of the game in the 88th minutes, but his shot went over.
The side's final game of 2020 is on Tuesday, when they travel to face Lincoln City (1pm kick-off).
IRON: Balme, Baker, Dawson, Gallimore, Kemp, Lobley (Lewis, 70), Virgo (Strouther, 88), Wilson, Young, Moore, Cribb (Moore-Billam, 77).
IRON UNUSED SUBS: Foster.