An applicator instrument for dispensing surgical fasteners includes a housing, an elongated shaft having a proximal shaft section and an articulating distal shaft section extending from the housing, a firing system disposed within the housing, an actuator that is engageable for commencing a firing cycle of the firing system, and an articulation lever provided on the housing for selectively articulating the articulating distal shaft section of the elongated shaft. The applicator instrument includes a cam plate disposed within the housing that is linked with the articulating distal shaft section and that coupled with the articulation lever for being rotated by the articulation lever between a first or horizontal position for straightening the articulating distal shaft section and a second or vertical position for articulating the articulating distal shaft section. An over-center assembly is coupled with the cam plate for forcing the cam plate into either the first position for straightening the articulating distal shaft section or the second position for articulating the articulating distal shaft section.