Leon Knight scored a first-half hat-trick on his debut to take Swansea City back to the top of League One.
Leon Knight celebrates scoring a hat-trick on his Swansea City debut
The £125,000 signing from Brighton opened the scoring in the fourth minute with a first-time shot into the corner.
He steered the ball between the legs of Dons goalkeeper Matt Baker for his second, before completing his hat-trick with a 27th-minute header.
Izale McLeod scored in the 80th-minute for the Dons from a re-taken penalty after his first attempt had been saved.
Swansea: Gueret, Ricketts, Tate, Monk, Austin, Britton, Martinez, Robinson, Williams (McLeod 90), Akinfenwa (Connor 73), Knight.
Subs Not Used: Murphy, Forbes, Goodfellow.
Goals: Knight 5, 12, 27.
Milton Keynes Dons: Baker, Crooks (Rizzo 45), Morgan, Chorley, Ricketts (Quinn 64), Lewington, Small (Wilbraham 70), Mitchell, Edds, Platt, McLeod.
Subs Not Used: Kamara, McKoy.
Booked: McLeod, Lewington, Chorley.
Goals: McLeod 81 pen.
Ref: S Mathieson (Cheshire).