  We classify simply connected compact Sasaki manifolds of dimension $2n+1$
with positive transverse bisectional curvature. In particular, the K\"ahler
cone corresponding to such manifolds must be bi-holomorphic to
$\C^{n+1}\backslash \{0\}$. As an application we recover the Mori-Siu-Yau
theorem on the Frankel conjecture and extend it to certain orbifold version.
The main idea is to deform such Sasaki manifolds to the standard round sphere
in two steps, both fixing the complex structure on the K\"ahler cone. First, we
deform the metric along the Sasaki-Ricci flow and obtain a limit Sasaki-Ricci
soliton with positive transverse bisectional curvature. Then by varying the
Reeb vector field along the negative gradient of the volume functional, we
deform the Sasaki-Ricci soliton to a Sasaki-Einstein metric with positive
transverse bisectional curvature, i.e. a round sphere. The second deformation
is only possible when one treats simultaneously regular and irregular Sasaki
manifolds, even if the manifold one starts with is regular(quasi-regular), i.e.
K\"ahler manifolds(orbifolds).
