  We present a lattice QCD based determination of the chiral phase transition
temperature in QCD with two massless (up and down) and one strange quark having
its physical mass. We propose and calculate two novel estimators for the chiral
transition temperature for several values of the light quark masses,
corresponding to Goldstone pion masses in the range of $58~{\rm MeV}\lesssim
m_\pi\lesssim 163~{\rm MeV}$. The chiral phase transition temperature is
determined by extrapolating to vanishing pion mass using universal scaling
analysis. After thermodynamic, continuum and chiral extrapolations we find the
chiral phase transition temperature $T_c^0=132^{+3}_{-6}$ MeV. We also present
some preliminary calculations on interplay of effective $U_A(1)$ restoration
and chiral phase transition towards chiral limit.
