The study investigates the formation of supersonic micro-jets by the interaction of two cavitation bubbles generated in anti-phase. High-resolution numerical simulations and experiments reveal that under specific conditions, the collapse of a toroidal shock wave and the necking of the bubbles lead to the generation of a supersonic jet with velocities exceeding 1000 m/s. The jet's formation is facilitated by the collapse of a parabolic neck, which emits a shock wave that triggers the neck's contraction and subsequent jet ejection. The jet remains stable and can be used for applications such as needle-free injections. The mechanism is validated through high-speed imaging and numerical simulations, showing excellent agreement in the dynamics of bubble pair interaction and jet formation. The study identifies a narrow range of standoff distances (0.7 to 0.8) where this phenomenon occurs, highlighting the importance of this mechanism in focusing kinetic liquid energy through resonant inertial cavitation bubble dynamics.The study investigates the formation of supersonic micro-jets by the interaction of two cavitation bubbles generated in anti-phase. High-resolution numerical simulations and experiments reveal that under specific conditions, the collapse of a toroidal shock wave and the necking of the bubbles lead to the generation of a supersonic jet with velocities exceeding 1000 m/s. The jet's formation is facilitated by the collapse of a parabolic neck, which emits a shock wave that triggers the neck's contraction and subsequent jet ejection. The jet remains stable and can be used for applications such as needle-free injections. The mechanism is validated through high-speed imaging and numerical simulations, showing excellent agreement in the dynamics of bubble pair interaction and jet formation. The study identifies a narrow range of standoff distances (0.7 to 0.8) where this phenomenon occurs, highlighting the importance of this mechanism in focusing kinetic liquid energy through resonant inertial cavitation bubble dynamics.