The Scottish forward was only playing because Matt Done was ruled out with a broken jaw – a casualty of the 3-3 Yorkshire derby with Bradford City previous time out – but he made an immediate impact.
First, the 23-year-old former Livingston attacker netted in front of the Kop after just five minutes.
Then, after Darren Potter equalised just after half-time, Scougall turned provider to gift Billy Sharp his 10th goal of the campaign.
“It was unfortunate for Doney to miss out, but it was a chance for me to come in and try to stake a claim,” said Scougall.
“I thought I did well, got a goal and an assist, but the main thing was that we got three points. I got the man-of-the-match champagne and, if we get a few days off now, I might have a little swig.
“That (win) shows the character in abundance. It showed we’ve got a character and a fighting spirit and a togetherness that shone through in the end.
“We didn’t play that well, but I thought we deserved to win.
“They’re a good side and they’ll beat teams towards the top of the table. They’ll pick up, don’t worry about that. But we were clinical when it mattered.”
When it comes to clinical, Sharp is head and shoulders above the rest in League One.
His fifth goal in three games was a poacher’s effort, and Scougall had no doubts of the outcome.
“I saw Coutts try and get a diagonal, but was expecting their full-back to clear it,” said Scougall. “I don’t know if I went over the top of him or what but I managed to keep it in, get the ball to Sharp and then he did the rest.
“If you give the ball to Sharp in the box, he’s going to score. Simple.
“When you have someone in the team like him, you know you are going to get goals. He’s proved that.
“So, as players, if we put the ball in the right areas, you know he is going to get on the end of them and put them away.”
Victory extended United’s unbeaten run to 11 games, but unlike the thrashings handed out to Port Vale and Shrewsbury – or the free-flowing 3-3 draw at Bradford – this was a gritty display.
“You need that fight and that ability to get results like this if you want to be successful over the course of the season,” said Scougall.
“The confidence is flying through the squad. There’d be something strange, after 10 (unbeaten) and now 11, if it wasn’t.
“But not just the lads who have been in the starting XI for a while. The same goes for the lads who have stepped in, and I think you need that.”
United took the lead following John Fleck’s corner, when Scougall scuffed his shot, and the ball rolled inside David Martin’s right-hand post.
Blades manager Chris Wilder had warned MK Dons would be dangerous opponents, and while they rarely threatened in attack, they did enjoy chunks of possession.
But United struggled to find a second goal, Daniel Lafferty heading into the side-netting while Sharp fired wide.
The Blades might have paid for their missed chances when Potter sidefooted home from the edge of the penalty area, following good work from Dean Bowditch and Dean Lewington.
But the Blades grabbed what proved the winner on 64 minutes when Scougall kept Paul Coutts’s diagonal ball alive before teeing up the predatory Sharp, who netted one of the easiest goals of his career from six yards out.
Substitute Caloan Lavery came close to grabbing a third goal, but fired wide, while at the other end Bowditch was off target from a corner.
“They made us work, MK Dons are in a false position, we knew that with the players they have got on the pitch,” said Blades boss Wilder. “The way they play, they keep possession, but I have to say I don’t think they created many clear-cut chances.
“Their shape is dangerous to play against, and it was a dangerous game. You look at their bench compared to our bench, I have got a youth team on my bench.
“It was a tough game. Even though we are at the back end of October, it was a big result for us.
“We conceded a goal, it’s not the end of the world. What’s their reaction? I thought it was outstanding and we pushed for a winner.
“Just like last week, we got pegged back and went again.”
Former Barnsley striker Done is out for a fortnight and will miss forthcoming Cup games against Leyton Orient and Grimsby, but could feature against Chesterfield on November 13.
He picked up the injury at Valley Parade, but Wilder kept the injury under wraps in the build-up to Saturday’s game.
He said: “We lost Matt Done, which was a big blow. We feel we have been a little bit unlucky with injuries, losing Done to an innocuous challenge which has fractured his jaw.
“We will have to wait and see, but Done is out for next week.
“Chesterfield is after that and hopefully we will have Leon (Clarke) back for that. (Done) can’t have any physical contact, can’t head the ball. It’s disappointing for him because he has put some right shifts in for us.”
Sheffield United: Moore, Basham, Ebanks-Landell, Wright, Freeman, Coutts, Duffy (O’Connell 90), Fleck, Lafferty, Scougall (Lavery 73), Sharp. Unused substitutes: Ramsdale, Brown, Chapman, Whiteman, Brooks.
MK Dons: Martin, Baldock, Hendry, Walsh, Lewington, Carruthers (Agard 28), Potter, Upson, Reeves, Bowditch (Powell 79), Colclough (Maynard 61). Unused substitutes: George B Williams, George C Williams, Nicholls, Downing.
Referee: S Hooper.
Man of the match: Stefan Scougall.