Australia's Melanie Schlanger qualified second fastest for the final of the women's 100 metres freestyle final at the Aquatics Centre in London.
Schlanger, who won gold on Sunday in the 4x100m freestyle relay, produced a powerful finish to touch the wall in 53.38 seconds, having made the turn at the 50-metre mark of her semi-final in fifth place.
Ali Herasimenia of Belarus was second in 53.78 and American Jess Hardy third in 53.86.
The Netherlands' Ranomi Kromowidjojo was fastest qualifier in winning the second semi-final in an Olympic record of 53.05.
Meanwhile, China added another gold medal to its haul with Jiao Liuyang winning the 200m butterfly final in an Olympic record of 2:04.06.
Mireia Belmonte Garcia of Spain won silver in 2:06.62 and Japan's Natsumi Hoshi claimed bronze in 2:06.37.