Jabo Ibehre had scored twice for the Saddlers with bursts through the middle of the visitors' defence in the 14th and 28th minutes to take his season's total to 10.
It looked all over but Huddersfield's veteran striker Andy Booth had other ideas and scored twice to bring the scores level before the interval.
He notched his first in the 43rd minute with a low drive on the half-volley from Danny Cadamarteri's cross but Walsall keeper Rene Gilmartin was at fault allowing the ball to squirm from his grasp and over the line.
Booth then headed his sixth of the season and third in two matches from Jim Goodwin's corner seconds from half-time and the visitors were comfortably the better side in the second half.
And the winning goal arrived in the 63rd minute when Goodwin found Martin Kelly, on loan from Liverpool, who turned quickly to send a left-foot shot inside the far post for the first goal of his senior career.