Two years to the day since winning her first World Cup event in Lienz in the giant slalom, the 24-year-old claimed her fifth World Cup victory on the same slopes.
Fenninger clocked a combined total of two minutes 17.00 seconds for her two runs, placing second on each run, to add to her victory on December 28, 2012, in Semmering.
Sweden's Jessica Lindell-Vikarby set the fastest time on the first run of 1min 08.63secs to Fenninger's 1:08.65, but had to settle for second overall after slipping back on the second run.
Fenninger clocked 1:08.35 on her second run, behind only Italian Denise Karbon, who finished 10th overall.
Mikaela Shiffrin of the United States was third overall.
"I really love Lienz and the slope," Fenninger told fis-ski.com.
"I can't explain why I am successful on that specific day. It's just amazing to win again.
"I have good memories of my fist victory here and it helps a bit for sure."