  We report the results obtained from ISAAC/VLT near-IR spectroscopy of two
low-luminosity z ~ 1.9 galaxies located in the core of the lensing cluster
AC114. The amplification factor allowed to obtain, for the first time, physical
properties (SFR, abundance ratios, mass, etc) of star-forming galaxies, 1 to 2
magnitudes fainter than in previous studies of Lyman-break galaxies at z ~ 3.
