A seventy-fourth minute penalty settled the game as Joe Whight (pictured) slotted home from the spot after Mekhi McKenzie had been taken out on the edge of the penalty area.
The runaway league leaders AFC Hornchurch came to King’s Marsh with only only defeat on the road so far this season, but the Sudbury side were more than equal to the task.
A goalless first half saw neither side have any real chances apart from inside thirty-five seconds when Chris Assombalonga was clear through and should have scored but skewed his shot wide of Paul Walker in the Sudbury goal.
Tyler French at the heart of the Sudbury defence was back to his best with a superb display of defending, heading and tackling brilliantly.
The second period saw both sides going for the victory and after Sudbury broke from a Hornchurch corner McKenzie was upended for the penalty from which the winner came.
Sudbury move up one place to ninth in the Bostik North table.
Updated 17:07 - 17 Feb 2018 by Tony Simpson