Forward Blazej Skoczylas scored both goals for the Lions, he struck the first at 51 minutes following a hard fought scoreless first half, and scored the second five minutes later when he beat London goalkeeper Scott Mueller from the penalty spot following a hand ball inside the box by Sergio Siguenza.
Brampton jumped two positions out of the cellar following the win, they now have a 2-7-1 WLT record for 7 points, while London City are at 1-5-2 with 5 points.
London will look to recover when they travel to Quebec next Saturday for an encounter with the Montreal Impact Academy.