The coed event pits 15 national teams of racers competing in head-to-head heats, and the Austrians have medaled in each World Championships edition.
Tuesday was the first year in which the Austrians won the gold.
"We have a great spirit inside the Austrian team and this has been a confirmation of our perfect shape. We are now really looking forward to the next events," said Matthias Berthold, captain of the Austrian men's team.
Sweden knocked out the U.S. team in the quarterfinals and Germany ousted Canada.
The worlds resume Thursday with the women's giant slalom.
Swim Week Miami Beach 2014 [PHOTOS]