A Gboly Ariyibi screamer in the second half of extra time eventually saw MK Dons past League 2 Forest Green Rovers and into the hat for the second round of the Carabao Cup.
Ariyibi's strike four minutes into the second period of extra time came after the home side had clattered the crossbar through substitute Scott Laird following a nip-and-tuck opening 90 minutes at The New Lawn.
Robbie Neilson made three changes to the side which lost 1-0 to Wigan at the weekend. Scott Wootton was serving his ban for being sent off, and with Joe Walsh still suspended, Paul Downing played alongside Ethan Ebanks-Landell. Dean Lewington struggled against Wigan and was dropped to the bench in favour of youngster Callum Brittain, and Kieran Agard made way for Robbie Muirhead.
In a far cry from Saturday's robust midfield battle, Dons were given considerably more freedom to play their game and were almost invited to attack by Rovers, who opted to sit deep. Dons weren't going to turn down the chance either, but Gboly Ariyibi and Ous Cisse both saw their efforts deflected wide of the upright, not testing keeper Sam Russell.
Dons did have the best chance of the half though, but it fell to an unlikely candidate to open the scoring. Clever footwork from Ariyibi gave him time to pick a pass across the face of goal. But while it was behind Ryan Seager, it fell to the left boot of Paul Downing, who looked surprised it made to him, and his tame strike was routinely saved by Russell.
But with 15 minutes of the first half remaining, Forest Green began to venture forwards and cause Dons a few problems. Christian Doidge was the main outlet for the home side, and having scored both goals against Barnet at the weekend, was full of confidence in taking on the Dons defence. Lee Nicholls though, like counterpart Russell, remained untroubled.
The second half appeared to be a lot more open, especially in the early stages, and was end-to-end. Downing missed another great chance, this time heading well wide from Ariyibi's corner but Rovers should have taken the lead just before the hour mark when Doidge scooped Luke James' cross just wide of Nicholls' post.
Mark Coopers' side were given a jolt in the arm when Shamir Mullings and Drissa Traore were brought on, and it was the former who twice tested Nicholls within minutes of his introduction that really livened the home support.
At the other end though, Ed Upson fizzed a couple of changes just over the bar, while substitute Kieran Agard too put one wide, but with neither side finding the net, it brought about extra time.
While both sides looked tired and going through the motions in extra time, Scott Laird came within the width of the crossbar of giving Rovers the lead, clattering the overhead with a free header within seconds of being introduced.
It would be the visitors though who would finally make the break through, and it would come four minutes into the second half of extra time. Ariyibi, who looked one of the more forlorn players on the pitch, received the ball on the left flank but cut inside onto his right foot and sent a fine strike across Russell and into the far corner to send Dons into the next round.
Referee: Anthony Backhouse
Attendance: 1,608 (341)
Forest Green Rovers: Russell, Bennett, Collins, Monthe (Laird 102), Noble, Doidge (Mullings 72), Brown (Marsh-Brown 57), Cooper, Fitzwater, Wishart (Traore 72), James
Subs not used: Pickering, Bugiel, Evans
MK Dons: Nicholls, Brittain (Lewington 105), Ebanks-Landell, Downing, Williams, Upson, Tshibola, Cisses, Ariyibi, Muirhead (agard 62), Seager (Nombe 79)
Subs not used: Sietsma, McGrandles, Rasulo, Thomas-Asante
Booked: Cisse, Ebanks-Landell, Williams, Downing