A method of completing a wellbore involves placing a series of sliding sleeves along a string of production casing in the wellbore and includes dropping a frac ball into the wellbore and landing it on a seat associated with an uppermost sleeve. Pressure is applied to activate the sleeve, open ports along the casing, and fracture a surrounding subsurface formation at a selected zone. Ball sealers are pumped down the well and seated within the sleeve ports. Additional fluid pressure is applied to cause the sleeve to shift further down the well and to release the ball, whereupon the frac ball is pumped to a next lower sleeve. This process may be repeated for multiple sleeves at multiple zones for top-down, multi-stage perforations. A novel sliding sleeve that permits a single ball to be used for activating multiple of the sleeves in series, from heel-to-toe, is also offered.