Neureuther was just too good second time out in Switzerland as he clocked runs of 1:17.46 minutes and 1:17.14 for an overall winning time of 2:34.60 and margin of 0.10 seconds.
He was seventh fastest in run one but overcame fading sunshine to post an unbeatable time and follow up his win last time out in Bormio in perfect fashion.
Frenchman Thomas Fanara tried his best to overhaul Neureuther and claim his first World Cup win ever but he couldn't while Austrian Marcel Hirscher was third a further 0.09 behind.
Neureuther's success was significant in many ways as he overtook his father's own World Cup tally of six while becoming only the second man from a German state to win such an event.
It was also important for Hirscher and American Ted Ligety as the pair missed out on the top two in a World Cup giant slalom for the first time in 18 races, that period spanning more than two years.
Olympic champion Ligety skied out midway down while Aksel Lund Svindal was 12th but managed to retain his lead in the overall World Cup standings.