In this letter, we present high-performance GaN-on-Si metal-oxide-semiconductor high electron mobility transistors with record reverse-blocking (RB) capability. By replacing the conventional ohmic drain with a hybrid tri-anode Schottky drain, a high reverse breakdown voltage (V-B(R)) of -900 V was achieved (at 1 mu A/mm with grounded substrate), along with a small reverse leakage current (I-R) of similar to 20 nA/mm at -750 V. The devices also presented a small turn-ON voltage (V-ON) of 0.58 +/- 0.02 V, a small increase in forward voltage (Delta V-F) of similar to 0.8 V, a high ON/OFF ratio over 1010, and a high forward breakdown voltage (V-B(F)) of 800 V at 20 nA/mm with grounded substrate. These results demonstrate a new milestone for RB GaN transistors, and open enormous opportunities for integrated GaN power devices.