Ellen Gandy and Jemma Lowe have qualified for the Team GB Olympic squad in the 200m butterfly.
Gandy was able to hold off Lowe with a time of 2m 06.01s in their race at the Aquatics Centre in London.
The 20-year-old will also represent Britain in the 100m butterfly following her triumph at the weekend.
Elsewhere, Andrew Willis and Michael Jamieson booked their places in the Olympic team in the 200m breaststroke.