A semiconductor device and method. The device includes a first domain and a second domain each having a power rail and a ground rail. The device further includes a signal line connected between the first domain and the second domain. The device also includes an electrostatic discharge protection circuit for providing cross-domain ESD protection. The protection circuit includes a blocking transistor connected between the first domain power rail and the signal line. The protection circuit also includes a power rail clamp connected between the first domain power rail and the first domain ground rail. The power rail clamp is operable to apply a control signal to a gate of the blocking transistor to switch it on during normal operation and to switch it off during an ESD event. The power rail clamp is operable during the ESD event to conduct an ESD current.