A two-piece, single-use, disposable lancet assembly includes a housing containing a lancet formed from a spring wire integrally formed with a sharpened, skin-piercing probe end section. The spring lancet is mounted within the housing and is secured in a retracted, pre-tensioned or cocked position. A lever-like bar hingedly secured to the housing serves both as a closure for the access opening in the housing and as a lever for dislodging and for releasing the tensioned spring wire to actuate the skin-piercing probe to pulse functionally through a base port in the housing and then automatically to retract irretrievably into the housing.