Combination of self-propagating high-temperature synthesis (SHS) from Ti + B powder mixture followed by spark plasma sintering (SPS) is introduced for the fabrication of titanium diboride. Oxide impurities, including zirconium oxide and titanium oxide, are identified in the synthesized powders: the first one coming from the milling process after SHS to minimize agglomeration and the second one is a common oxide fine layer on particle surface. Both oxide phases are reduced during SPS treatment. Results confirm that increasing the SPS temperature enhances the reduction of ZrO2, facilitating the incorporation of Zr cations into the lattice through substitution at Ti sites, thus allowing the formation of this solid solution diboride: Ti1-xZrxB2. The key finding is that the presence of a small amount of Zr cation, with higher atomic radius in TiB2 crystal structure results in crystal distortion and it creates significant solid solution hardening effect as well as an improved wear response.