  We present a new mechanism for $B^{\pm}\to \eta' K^{\pm}$, and analyze it
strictly within perturbative QCD. We find that such a new mechanism may
dominate non-leptonic $B$-decays to light mesons. Within a reasonable parameter
space, our prediction is in good agreement with the recent CLEO data on
$B^{\pm}\to \eta' K^{\pm}$. We conclude that there is no room for an abnormally
large \bsg vertex from physics beyond the Standard Model.
