The Bees earned their first away clean sheet of the season in a 1-0 win at Colchester United, Alex Nicholls' second half strike the difference between the two sides.
An icy, strong wind swirled around the Weston Homes Community Stadium and it took a while for both sides to adjust to the difficult conditions.
Ryan Watson's effort in the 15th minute went across the face of goal and narrowly wide before Mandron had a chance for the U's, but his volley was dragged past the post.
On the half-hour mark, Ryan Jackson had his shot from 6-yards out blocked and subsequently cleared by Ruben Bover.
Watson had another chance from Akinde's header but again it went the wrong side of the post.
Legg, making his professional debut, was forced to make a good save in first-half stoppage time. He was quick off of his line, made himself big and blocked Senior's effort.
Colchester, whose chances were few and far between, would live to rue their missed opportunities when the Bees took the lead in the 67th minute.
George Legg's long kick was brought down out of the sky by John Akinde. He shrugged off his marker before cutting inside and teeing up Alex Nicholls who would take one touch before firing across goal and finishing into the bottom left corner.
In truth, the hosts never really threatened Legg's goal for the remainder of the game, Frankie Kent with the best opportunity but he fired over the bar for the edge of the box.
Graham Westley picks up his first away win as Barnet Head Coach and the Bees pick up a crucial three points in their bid to beat the drop.
BARNET - Legg, Santos, Watson, Weston (c), Akinde, Coulthirst (Nicholson '86), Tutonda, Bover (J. Taylor '78), Vilhete, Nicholls, Sweeney.
Unused - Ross, Clough, Shomotun, Payne, Plavotic
Attendance - 3121 (235 Barnet)