The extremely stable high-power generation from hybrid piezoelectric nanogenerator (HP-NG) based on a composite of single-crystalline piezoelectric perovskite zinc stannate (ZnSnO3) nanocubes and polydimethylsiloxane without any electrical poling treatment is reported. The HP-NG generates large power output under only vertical compression, while there is negligible power generation with other configurations of applied strain, such as bending and folding. This unique high unidirectionality of power generation behavior of the HP-NG provides desirable features for large-area piezoelectric power generation based on vertical mechanical compression such as moving vehicles, railway transport, and human walking. The HP-NGs of ZnSnO3 nanocubes exhibit high mechanical durability, excellent robustness, and high power-generation performance. A large recordable output voltage of about 20 V and an output current density value of about 1 μA cm−2 are successfully achived, using a single cell of HP-NG obtained under rolling of a vehicle tire.