Patrick Bamford scored one and created another as MK Dons extended bottom side Notts County's winless start to the season.
Luke Chadwick swept home the opener on five minutes, latching onto a cut-back from Chelsea loanee Bamford.
Shaun Williams then curled in a 25-yard free-kick before Callum McGregor raced clear to score and give County hope.
Izale McLeod missed two late chances for the hosts before Bamford slammed in a loose ball on 90 minutes.
MK Dons manager Karl Robinson told BBC Three Counties Radio:
"You can hear the fans getting frustrated in the second half. We didn't play any different (to the first half), we just didn't take our chances.
"I don't think they could have had any qualms if we'd won that by five or six.
"We had probably better chances second half than first half, we just didn't put them away.
"When you look at the squad they've got (Notts County), that's not going to be a team down at the bottom."
MK Dons 01 Martin 02 Otsemobor 03 Lewington 06 Williams 24 Kay 07 Gleeson 08 Potter 10 Chadwick (Alli - 72' ) 22 Carruthers (Baldock - 85' ) 23 Green (McLeod - 72' Booked ) 15 Bamford Substitutes 16 McLoughlin 12 Reeves 14 Alli 18 Baldock 21 Banton 11 Smith 13 McLeod Notts County 01 Bialkowski 02 Dumbuya 03 Sheehan 04 Liddle 06 Leacock 05 Smith 08 McGregor Booked 11 Bell (Grealish - 59' ) 16 Labadie (Boucaud - 71' Booked ) 10 Haynes Booked (Arquin - 59' ) 12 Haber Substitutes 23 Speiss 07 Grealish 22 Fotheringham 25 Tempest 28 Boucaud 15 Arquin 19 Murray