A layer of or including substoichiometric zirconium oxide is sputter deposited on a glass substrate via a substoichiometric zirconium oxide inclusive ceramic sputtering target of or including ZrOx. The coated article, with the substoichiometric ZrOx inclusive layer on the glass substrate, is then heat treated (e.g., thermally tempered) in an atmosphere including oxygen, which causes the substoichiometric ZrOx inclusive layer to transform into a scratch resistant layer of or including stoichiometric or substantially stoichiometric zirconium oxide (e.g., ZrO2), and causes the visible transmission of the coated article to significant increase.