Meillard clocked the fastest first leg and held his nerve on the second run under floodlights for a winning aggregate of 2min 18.77sec.
His teammate Gino Caviezel was second, at 0.59sec, while Austria's Marco Schwarz rounded out the podium (+0.81).
Olympic champion Marco Odermatt, currently the leader in the World Cup overall standings, did not take part, the Swiss star preferring to rest a knee injured in Kitzbuehel's first downhill last Friday.