Neureuther, who competed at last month's Winter Olympics just five days after a car accident, was the most consistent over both runs to move into the World Cup lead in the discipline.
The 29-year-old German posted times of 52.94 and 52.56 seconds for an overall winning time of 1:45.50 minutes; 0.59 better than teammate Fritz Dopfer in second.
Norwegian Henrik Kristoffersen completed the top three a further 0.20 behind with just one more slalom race left this season as the World Cup comes to a close in Lenzerheide.
The race for the slalom Crystal Globe couldn't be tighter with Neureuther five points ahead of Marcel Hirscher, who was fifth in Slovenia, although the Austrian leads the World Cup overall.
Neureuther is bidding to become the second Germany to win the slalom World Cup tour; Armin Bittner the nation's only champion in 1989 and 1990.
- Sports & Recreation