The visitors went closest to scoring when left back Faouzi Ghoulam's superb lob from 25 metres struck the crossbar in the 33rd minute.
St Etienne now have the same points total (27) as fifth-placed Bordeaux and Lorient in sixth but possess a superior goal difference.
"We were very disappointed with last weekend's 1-0 home defeat (against leaders Lyon) but tonight we played great," St Etienne coach Christophe Galtier told the Canal+ Sport television station.
"We deserved a better result but I am really satisfied with the way we played and what we tried to do on a heavy pitch."
Lyon have 35 points from 17 matches.