Control Lyapunov function (CLF) methodology tries to minimize a quadratic cost-function as; V(x)=x^2, through a point-wise setup. However, optimal control minimizes a quadratic cost-function through a time-interval as; J(x)=int(x^2.dt,0..infinity), through the time axis.
Therefore, we may conclude CLF is equivalent to proportional-control, while optimal control is an integral-control methodology. The robustness of optimal-control is attributable to its integral format.