The Austrian gave the crowd plenty to shout about as she came home in 2:17.00 minutes for her second win in Leinz, having topped the podium back in 2011.
Just 0.50 seconds further back was Swede Jessica Lindell-Vikarby who had to settle for second, while American Mikaela Shiffrin took third.
Thanks to her victory Fenninger now sits second in the overall World Cup standings on 597 points, just 12 behind leader Tina Weirather after she was 17th in Leinz.
But it is still Lindell-Vikarby leading the way in the giant slalom ranks despite being second best in Austria.
Lindell-Vikarby has 332 points, 110 more than compatriot Maria Pietilae-Holmner with Weirather third on 219.
© Sportsbeat 2013