Kitajima rallied from third after 50 meters to win in 58.91 seconds Monday, bettering the old mark of 59.13 set by American Brendan Hansen two years ago.
Alexander Dale Oen of Norway took the silver in 59.20. Hugues Dugoscq of France earned the bronze in 59.37. Hansen was second halfway through the race, but faded to fourth. Six of the eight finalists swam under 1 minute.