MK Dons suffered back-to-back defeats for the first time this season as Brentford edged a nail-biting League 1 encounter at stadiummk.
The Dons desperately tried to claw their way back after going 2-0 down in the first half but even Shaun Williams' second penalty of the week wasn't enough as Jabo Ibehre hit the bar in the six minutes of injury time played.
After a promising start the Dons soon found themselves two-goals down with Clayton Donaldson and Jonathan Douglas both finding gaps in the defence with punishing strikes.
The Dons bossed the second half and deserved to find an equaliser earlier than they did, but it wasn't to be and they now have six games remaining to secure a place in the play-offs.
The Dons were forced into three changes due to injuries picked up in midweek with Dean Bowditch, Mathias Kouo-Doumbe and Luke Chadwick all ruled out. As a result, there was a surprise inclusion for James Tavernier who returned for a month out on the sidelines with a knee complaint. There was also room for Alan Smith and Jay O'Shea, who had both made substitute appearances against Carlisle United.
Within six minutes the Dons had already caused problems for the Bees' backline when Stephen Gleeson drove a fine effort just wide of the post before MacDonald saw his close-range shot parried by 'keeper Richard Lee.
The Dons looked lively in front of goal, keen to make amends for their defeat earlier in the week, but former Watford goal Lee showed signs of good form in the early stages and Jay O'Shea, after twisting and turning down the left flank, became another Dons player to be frustrated after Lee punched away his curling shot.
The home side were on top, but Brentford were dangerous on the counterattack and when Donaldson made a smart run to pick up a through ball which had cut the Dons apart, it was Robinson's men who were in trouble.
The powerful forward showed great desire to get the better of Tom Flanagan and when he broke into the six-yard area Donaldson was able to fire past David Martin from a tight angle.
After taking the lead, Brentford had the confidence to advance more often rather than soak up the pressure. Jonathan Douglas in midfield had the ability to pull the strings for the visits to release the Bees forward, but both Shaleum Logan and Sam Saunders sent wild efforts off target when they were expected to test Martin.
The Dons were out-of-sorts and lacked a spark as the Bees continued to look dangerous. When O'Shea lost possession on the edge of the Dons' box Brentford showed their sting when Logan sprayed the ball to Douglas who in turn curled a superb strike into the corner of the net.
Lacking their usual tempo, the Dons found it difficult to play their usual passing game meaning they had to chase the play more often.
A huge second half was required from the Dons and in the early phases Stephen Gleeson and O'Shea watched efforts fall wide as the home side tried to claw their way back.
The volume at stadiummk rose as decisions continued to go against them, much to the annoyance of the home crowd and the Dons' bench.
There was more meaning to the Dons' attacks but little was going their way in front of goal with Daniel Powell latching on to a cross from Smith and somehow keeping the ball in on the byline but MacDonald's touch took the ball inches wide of the near post.
Further frustration came when Douglas appeared to control the ball with his arm yet appeals for a penalty were turned down by the officials.
A rare shot on goal, possible due to frustration, came from the boot of Potter from the right touchline. It fizzed into the palms of Lee but was by no means a comfortable save for the Bees 'keeper.
Still threatening to find a route back into proceedings the Dons went all-out attack by introducing Rob Hall and Jabo Ibehre to strengthen up front, and setting out a three-man defence with Powell offering cover on the right when needed.
The danger though came when Brentford went on the counterattack and when Logan eased passed Williams there was only Martin to beat. However, the Dons number one was brave in his decision to make a telling block before the defence recovered to clear the lines. Smith did his best to stir the team into action in front of goal with a fine scissor-kick but a wicked deflection turned the shot off-target when it should have been nestling into the top corner.
Then, a great glimmer of hope came when MacDonald was tripped inside the area and the Dons were given a penalty with two minutes remaining. For the second game in succession Williams stepped up to tuck home a fine spot-kick and give the Dons great hope.
Six minutes of added time were shown and it gave the Dons licence to pile forward. Ibehre had two great opportunities to grab a draw when his shot hit the underside of the bar and bounced out, before sending another effort over.
The time ticked away but the Dons' efforts didn't whimper. Unfortunately time beat them and the Dons now head into the Easter period looking to seal the top six place.
MK Dons (4-2-3-1): Martin; Tavernier (Ibehre 73), Flanagan, Williams, Lewington (c); Potter, Gleeson; Powell, Smith, O'Shea (Hall 62); MacDonald.
Subs: McLoughlin, Chicksen, Slane
Booked: Smith, Flanagan, Potter, Lewington
Goal: Williams 88 (pen)
Brentford: Lee (c), Saunders (Bean 77), Douglas, Donaldson, Logan (Legge 90), Forrester (McGinn 64), Diagouraga, Osborne, Thompson, Bidwell, Dean.
Subs: Berahino, Morrison, Osborne
Booked: Lee, Thompson, Bean
Goals: Donaldson 12, Douglas 25
Referee: Gary Sutton (Lincolnshire)
Attendance: 11,570 (1,170)