Paris crossed the finish line in 1 minute, 57.56 seconds, 0.13 seconds ahead of Canadian Erik Guay, for his second World Cup win of the season and first at Kitzbuehel, a landmark in downhill skiing.
"To win Kitzbuehel is beyond what I could have dreamed of," Paris said after his flawless run.
"I really didn't expect it," Paris added. "I was not among the best in the training runs and I had no idea what to expect from the race. But I knew that I if I wanted to make a difference I would have to do that in the bottom section. I picked my line and was able to execute the plan perfectly."
Hannes Reichlet of Austria finished third in front of his home nation crowd. World Cup points lead Aksel Lund Svindal of Norway took ninth and Travis Ganong led the U.S. team with a 19th place.
Ganong, who was clocked at 1:59.32, said the Streif was a little icier and dicier than usual, particularly around the key Hausberg jump. "The speed coming off Hausberg onto the side hill at the bottom was a little faster today and that kind of threw some people off guard," he said. "Things were coming at you a lot quicker. That's where I had some problems too."