Observation Of D0-Meson Decay Into K-Pi+Pi0

In a sample of multihadron events with a ${\ensuremath{\pi}}^{0}$ from ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data at 3.77-GeV center-of-mass energy, we observe the decay ${D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0}$ with direct observation of the ${\ensuremath{\pi}}^{0}$. The observed branching fraction is (12\ifmmode\pm\else\textpm\fi{}6)%.