Ohlgren, who will be a senior for the 2009-2010 season at Auburn, swam a time of 4:40.61 to dominate the event. The runnerup, Hanna Pierse of Canada, was a distant second with a time of 4:50.49. Svetlana Karpeeva of Russia took the bronze medal in a time of 4:44.26.
Going into the competition the Auburn swimmer said she felt good about her training in AU's outdoor pool this summer as well as some late spring workouts at altitude in Colorado Springs, Colo.
The victory gave Ohlgren her third gold medal in international competition. She won a gold in the 200 individual medley at the 2007 Pan American Games and added another in the 4x200 freestyle relay at the same competition.
After shaving almost three seconds off her personal record, Ohlgren will compete in the 200 individual medley on Monday. With her victory in the 400 IM, it was the 37th gold medal won by an Auburn swimmer in the history of the World University Games.