In this work we present uni-directional GaN-on-Si MOSHEMTs with state-of-the-art reverse-blocking performance. We integrated tri-anode Schottky barrier diodes (SBDs) with slanted tri-gate field plates (FPs) as the drain electrode, and achieved a high reverse-blocking voltage (V-RB) of -759 +/- 37 V at 0.1 mu A/mm with grounded substrate. The hybrid Schottky drain did not degrade the ON-state performance when compared with conventional ohmic drain, and the turn-ON voltage (V-ON) was as small as 0.64 +/- 0.02 V. These results show the potential of GaN-on-Si transistors as high-performance uni-directional power switches, and open enormous opportunities for future highly integrated GaN power devices.