LEE NOVAK notched his fourth goal of pre-season and had a hand in the other two goals as Town came from behind to clinch their sixth win from as many senior friendlies.
Rotherham, having been on top in the first half, went ahead seven minutes into thr second when Chris Holroyd put away Adam Le Fondre's pass from close range.
But Donal McDermott picked up Novak's pass to slot a 65th-minute leveller through the legs of keeper Conrad Logan.
Novak then drilled home a 72nd-minute shot at the second attempt before setting up Jordan Rhodes, who fired in Town's third in the 83rd minute.
Novak, who had come on for Danny Ward soon after Rotherham's goal, had a late header from a Rhodes cross tipped onto the bar.