Tommy Miller set Ipswich on their way with a well-struck shot from 25 yards which flew past North End goalkeeper Andy Lonergan in the 11th minute.
Preston drew level in the 34th minute. It came from a fine pass from defender Callum Davidson, who found Chris Brown in space 25 yards from goal and he did the rest with a fine shot from distance
Preston began to up the tempo as the second half wore on and Neil Mellor was not to be denied in the 79th minute when he fired home left-footed from Simon Whaley’s left-wing cross.
But Walters displayed his own predatory instincts with three minutes remaining when he collected Owen Garvan’s pass and fired into the bottom left-hand corner.