American Katie Ledecky continued domination of the women's 800 meters freestyle with a brilliant swim to win gold.

Katie Ledecky stubbornly refused to give up her 800-meter freestyle crown Saturday at the world championships in Singapore, winning that race for a seventh consecutive time and fending off Canada's Summer McIntosh, who led a field of talented, young would-be usurpers.

Ledecky, trailing McIntosh at the 700-meter mark, surged ahead on the final lap, fending off a hard-charging Pallister as McIntosh faded in the closing meters. With the win, Ledecky remained undefeated in the 800-meter freestyle finals event on the world stage dating back to 2012.