Power is gated from global terrain to a voltage island while controlling leakage and managing transient power supply noise. The voltage island includes a field effect transistor (FET) power gate, a first connection to a global voltage source and a second connection to a disable signal source, and an island voltage net for supplying voltage to devices on the island. A power gate control circuit is responsive to the disable signal source for generating a test signal for selectively turning off the FET power gate as the disable signal source goes to a logical `1`, and for turning on the FET power gate as said disable source goes to a logical `0`. The FET power gate is responsive to the disable signal source being off for connecting the island voltage net to the global voltage source. A turn on finisher circuit is responsive to the disable signal transitioning to on and to the test signal for holding the power gate solidly on; and a turn off finisher circuit is responsive to the disable signal transitioning to off and to the test signal for holding said power gate solidly off.