Caernarfon toppled arch-rivals Bangor City with a late winner from recent signing Michael Bird.
The much-travelled striker, signed from Witton Albion, converted a free kick from a narrow angle with just six minutes left.
The visiting Citizens had taken control after keeper David Walsh had denied them through a first half of dominance in which Tony Gray and Clayton Blackmore could well have settled the game.
Welsh Under-21 cap Les Davies finally found the back of the net in the 54th minute with an eight yard header from a Simon Davies left-wing cross.
But the turning point came with the dismissal of City defender Phil Baker, who sent Canaries' front man Lee Jones sprawling. Jones dusted himself off to convert the spot kick and set-up a famous victory against their high-flying visitors.
