The United States set the world record in the 4x100 freestyle mixed relay, clocking 3 minutes, 18.48 seconds in the swim world championships.

Katie Ledecky won her seventh world title in the 800 meter freestyle on Saturday, Aug. 2 at swimming's world championships, just edging surprise Lani Pallister in a thrilling race while Ledecky's top rival Summer McIntosh finished third.

The United States set the world record in the 4x100 mixed relay, clocking 3 minutes, 18.48 seconds in the swim world championships

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.

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

Katie Ledecky won her seventh consecutive world title at the world championships in Singapore, on Saturday, Aug. 2, in the 800-meter freestyle. She also won gold in the 1,500m and bronze in the 400m races.