  Motivated by \cite{DG19}, we prove the global existence and large time
behavior of small solutions to 2-D Prandtl system for data with Gevrey 2
regularity in the $x$ variable and Sobolev regularity in the $y$ variable. In
particular, we extend the global well-posedness result in \cite{PZ5} for 2-D
Prandtl system with analytic data to data with optimal Gevery regularity in the
sense of \cite{Ger1}.
