Measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mi>−</mml:mi></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:mrow><mml:mover><mml:mrow><mml:mi>p</mml:mi></mml:mrow><mml:mrow><mml:mo>→</mml:mo></mml:mrow></mml:mover></mml:mrow></mml:mrow><mml:mi>η</mml:mi><mml:mi>Λ</mml:mi></mml:math>near threshold

We present measurements of the differential and total cross sections and the $\ensuremath{\Lambda}$ polarization for the reaction ${K}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\eta}\ensuremath{\Lambda}$ from threshold to ${p}_{{K}^{\ensuremath{-}}}=770\mathrm{MeV}/c,$ with much better precision than previous measurements. Our cross-section data show a remarkable similarity to the $\mathrm{SU}(3)$ flavor-related ${\ensuremath{\pi}}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\eta}n$ cross-section results. The reaction ${K}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\eta}\ensuremath{\Lambda}$ at threshold is dominated by formation of the intermediate $\ensuremath{\Lambda}(1670){\frac{1}{2}}^{\ensuremath{-}}$ state.