  Assuming Perelman's estimates, we give a new proof of uniform $L^\infty$
estimate along normalized K\"ahler-Ricci flow on Fano manifolds with
K\"ahler-Einstein metrics, using Chen-Cheng's auxiliary Monge-Amp\`ere equation
and the Alexandrov-Bakelman-Pucci maximum principle. This proof does not use
pluripotential theory.
