Jon Nolan’s third goal of the season has given Town a 1-0 half-time lead away against the MK Dons.
Town boss Paul Lambert named the same team which beat Rochdale 2-0 at Portman Road last weekend, while Kayden Jackson and Alan Judge returned to the 18 after injury.
Tomas Holy continued in goal behind a back four of - from the right - skipper Luke Chambers, Toto Nsiala, James Wilson and Stephen Ward.
In midfield Andre Dozzell was joined by Nolan and Teddy Bishop, while Oli Hawkins was the central striker with Gwion Edwards to his right and Freddie Sears to his left.
Jackson, who had been sidelined with a groin injury since pre-season, was on the bench for the first time this season where he was joined by Judge, who missed the last two matches due to a hamstring problem.
Luke Woolfenden, who has also been out with a groin injury, was initially named among the subs in error, and was at the ground, before the club issued a correction and included Emyr Huws instead.
MK Dons boss Russell Martin made five changes to the team which lost 2-0 at Crewe last week with veteran centre-half Richard Keogh, who the Blues were keen on in the summer, and Scott Fraser making their full debuts for the club.
George Williams returned from injury to make his first appearance of the season, while David Kasumu and Daniel Harvie also came into the XI.
The first chance of the game, played on a very wet pitch but with the rain having stopped, fell to the home side in the sixth minute, a loose ball dropping to Keogh in the area following a corner but the Irish international scuffed to Holy.
Within a minute, the Blues were in front. After Hawkins picked up a loose pass from Keogh on the right, Edwards crossed and Sears sent it back in from the left, past Bishop as he and a defender tussled.
Edwards, who had made his way to the edge of the six-yard box, sought to chest it down and it fell to Nolan, who hit into the ground and past home keeper Lee Nicholls for his third goal of the season, already one more than he scored in 2019/20.
Town were close to making it 2-0 in the 18th minute when Wilson intercepted a pass on halfway and brought it forward before playing it Sears to his left. The former West Ham man cut in and hit a curling shot which flew just past Nicholls’s left post.
The Blues were forced into a change in the 22nd minute when Ward, who had undergone treatment for what appeared to be a groin problem after the Town goal, made his way off with Myles Kenlock taking over and making his first league appearance of the season.
The home side were seeing most of the ball but without looking threatening, while the Blues appeared potentially more dangerous every time they broke, usually through Sears.
On 26 Dozzell played a looping ball over the top for Hawkins, who took it down but shot deep into the empty stand behind the goal.
However, it was the Dons who were seeing virtually all of the ball but with the Town backline resolute and Holy not forced into a save.
There was a big scare for the Blues in the 33rd minute when Kenlock’s loose pass back to Holy from the right played Carlton Morris in on goal. However, as the keeper advanced, Chambers slid in superbly to send the ball behind. From the corner, Keogh’s looping header was claimed by Holy.
In the 36th minute Harvie was probably lucky to see only a yellow card after kicking out at Chambers with the ball long gone.
Play continued and home skipper Lewington prevented Nsiala from putting it out of play for the Blues captain to receive treatment before referee David Rock stopped play, liaised with his fourth official, cautioned Harvie and awarded Town a belated free-kick.
That stoppage and a subsequent interruption for a Dons injury briefly knocked the home side off their stride and the Blues began to see more of the ball, albeit in their own half of the field.
In five minutes of injury time, Nsiala blocked from Mason on the edge of the box with the Dons again dominating possession.
Just before the whistle, the former Wolves, Cardiff and Plymouth man should have levelled. Having been played in behind the Town backline on the left of the box the forward hit a low shot which the advancing Holy saved with his feet, much to the frustration of home manager Martin on the touchline.
That was the final chance of a half in which the Dons had had the lion’s share of the possession but had been unable to create a really serious chance until Mason’s effort just before the end.
Town, having got their noses in front, seemed not unhappy allowing the Dons the ball and attempting to break on them, which might well have led to a second goal through Sears.
MK Dons: Nicholls, Williams, Lewington (c), Keogh, Kasumu, Morris, Fraser, Sorensen, Mason, Harvie, Brittain. Subs: Walker, Poole, Cargill, O’Hora, Nombe, Houghton, Sorinola.
Town: Holy, Chambers (c), Nsiala, Wilson, Ward (Kenlock 22), Dozzell, Nolan, Bishop, Edwards, Sears, Hawkins. Subs: Cornell, Huws, Downes, Judge, Lankester, Jackson. Referee: David Rock (Hertfordshire).