Sean O'Hanlon returned to haunt his former side Swindon Town as his first-half header proved decisive in MK Dons' 1-0 win at the County Ground.
The centreback nodded home the winner in the 17th minute to maintain the Dons'&nbsp;seven point cushion in the League 1 play-offs and leave Swindon in a desperate fight to avoid relegation to League 2.
Swindon, reduced to ten men late on when Andy Frampton picked up his second caution, had chances to take a point in the scrappy match as Alassane N'Diaye hit the bar on the stroke of half-time, but they could not break the Dons' defence.
Karl Robinson's men enjoyed the better of the football and were in control for large spells of the game, but a poor second half always made the task of adding to the score a difficult one.
Luke Chadwick contests the ball in midfield
The Dons made two changes to the side that recorded a dramatic 3-2 win over Carlisle United a week earlier with Gary MacKenzie returning from injury and Jabo Ibehre&nbsp;in the starting line up in place of Rowan Vine. Injury to Danny Woodards forced Robinson to reshuffle his backline with Mathias Kouo-Doumbe moving into right-back and MacKenzie partnering Sean O'Hanlon in the centre.
Former Don Jon-Paul McGovern wasted a glorious opportunity in the opening minutes to test David Martin when a free-kick from the left-hand side was drilled low in an attempt to play Matt Ritchie through but a heavy touch saw the ball trickle out for a goal kick.
The Dons looked comfortable in possession as Swindon struggled to keep their composure on the ball. There was plenty of attacking intent from the Dons as Daniel Powell proved to be a handful in the early stages.
Jabo Ibehre holds off pressure as the Dons dominate at the County Ground
The wide man picked up the ball that was retained well by Ibehre on the edge of the box and, after bettering his sight at goal by shifting into the middle, forced a fumbled stop from Phil Smith.
It was that man Powell who again caused the Town defence a headache as he caught Alan Sheehan cold with&nbsp;a ball threaded through his legs as he moved into the right of the box. Only a strong clearance from Jonathan Douglas prevented Ibehre converting the cross that followed from six-yards out.
With the Dons in full control it was only a matter of time until Town's defence cracked and in the 17th minute they found the break through from a set-piece that was poorly marked by Swindon.
As he has all season, Peter Leven whipped in a great corner from the right and waiting at the back post was former Town defender O'Hanlon to emphatically headed past Swindon 'keeper Smith.
Sean O'Hanlon celebrates with his team mates after scoring against his old side
The County Ground became growingly impatient with the home side and their lack of fluidity in pressing forward, but Swindon did have a brief spell of pressure although finding a way through the Dons' defence proved difficult.
N'Diaye found the ball at his feet as he broke into the final third and as his shot was blocked David Prutton picked up the loose ball, yet MacKenzie and Dean Lewington stood firm.
Matt Richie had an effort from inside the 18-yard box diverted for a corner by Kouo-Doumbe, and from the resulting set play both Douglas and McGovern saw fierce volleys deflected.
Town were denied an equaliser by the woodwork seconds before the half-time whistle when McGovern collected a misplaced pass to feed Prutton through on the right. Prutton noticed the run of N'Diaye into the box, but as the forward slid in he hit the ball against the underside of the bar and was left wondering how the score was not level.
Kouo-Doumbe battles against former Don Jon-Paul McGovern
Three minutes into the second half Town once again edged close to finding the leveller when Ritchie picked up a header by O'Hanlon and his low drive forced a tip away by Martin before Prutton could follow up to tap in.
With emotions running high in the game a disagreement broke out between the two benches and the referee&nbsp;sent Paul Hart's number two Ian McParland to the stands. It came at a time when the play on the pitch became largely interrupted by fouls as the game turned scrappy.
It was through the set-pieces that Swindon looked most likely to score from, but when a Luke Chadwick foul presented them with a free-kick at the right of the box Ritchie sent his delivery straight into the grateful arms of Martin.
With Swindon still threatening the Dons made positive substitutions to push on for a second with Baldock and Angelo Balanta adding&nbsp;strength to their attacking line.
Daniel Powell caused Swindon an array of problems
However, it was O'Hanlon who caused problems again for Town when he went unmarked at Leven corner but sent a free-header wide of the post.
Swindon continued to huff and puff in front of goal and the Dons supporters were left to hold their breaths as Elliot Benyon's header was saved on the line by Martin, and the Dons goalie was bundled over into the net by Prutton, but the foul was spotted by the officials.
Town's afternoon went from bad to worse eight minutes from time when Frampton picked up his second booking of the afternoon, his first for dissent, when he fouled Ibehre and the home side were forced to end the game with 10 men.
Swindon Town: Smith, Douglas (c), Frampton, Caddis, McGovern, Prutton, Jean-Francois, Sheehan (Rose 75), Ritchie, N'Diaye (Benyon 57), Andrew
Subs: Lucas, Bodin, Ferry, Timlin, Cuthbert
Booked: Frampton, Caddis
Sent-off: Frampton 82
MK Dons (4-2-3-1): Martin; Kouo-Doumbe, O'Hanlon, MacKenzie, Lewington; Gleeson, Leven; Powell (Baldock 72), Chadwick, Marsh-Brown (Balanta 64); Ibehre.
Subs: Searle, Vine, Chicksen, Flanagan
Booked: Kouo-Kouo-Doumbe, Gleeson, Balanta
Goal: O'Hanlon 17
Referee: J Linington
Attendance: 8,305 (655 away)