BEIJING — Yelena Isinbayeva of Russia has broken her own world record in winning a second consecutive Olympic pole vault gold medal.

Already assured victory over rival Jenn Stuczynski of the United States, Isinbayeva set the mark of 16 feet, 6 3/4 inches (5.05 meters) on her third and final attempt at that height Monday night.

After eclipsing her old record by a quarter of an inch (1 centimeter), Isinbayeva did a somersault on the mat before jogging around the Bird’s Nest track with a Russian flag. It was the third track and field world record at these Olympics.

Stuczynski’s top height was 15-9 (4.80 meters), while bronze medalist Svetlana Feofanova of Russia, the 2003 world champion, topped out at 15-7 (4.75 meters).