Taylor, who Rotherham tried to sign in 2013, had not scored in 21 games going back to March but he made amends to earn the Dons the points in style, scoring two goals to clinch the game after Joe Newell's fine equaliser for the Millers.
His first came after only 15 minutes as he coolly clipped home after Andy Barcham's brilliant slide-rule pass cut the visitors wide open.
It was a rampant start for the Dons and only a brave header from Kieffer Moore kept Rotherham's deficit at one, when he cleared off the line.
The Millers were far better after the break but it was the hosts that went closest to scoring again, with Harry Forrester's delightful chip pushed on to the crossbar by goalkeeper Richard O'Donnell just after the hour-mark.
And that save proved important as in the 71st minute Rotherham levelled with a moment of real quality as Newell let fly with a first-time volley from 20 yards that rifled into the bottom corner.
Just as it looked like the Millers would push on and try and force a fourth win on the spin, Taylor struck again in the 86th minute, cutting in from the left and drilling home from 18 yards, and then completed his treble in time added on after a horrible mistake by Richard Wood.