Ariarne Titmus

Katie Ledecky started the United States' medal collection at the world swimming championships with a gold by reclaiming her title in the women's 400 meters.

The Americans finished the first day of racing with two gold, one silver and three bronze.

Australia’s Ariarne Titmus may have knocked out American Katie Ledecky in the 400-meter freestyle at the Tokyo Olympics

Australia's Ariarne Titmus won a thrilling 400m freestyle duel with American great Katie Ledecky in the Olympic pool on July 26 as Caeleb Dressel launched his bid for a seven-gold spree in style.

The Tokyo Aquatics Centre also witnessed a dominant 100m breaststroke swim by world record holder Adam Peaty, who defended his title to give Britain its first gold medal of the Games.