Fran Halsall, Ellen Gandy and Jemma Lowe have all made it successfully through the heats of the 100m butterfly.
British record holder Halsall was the second faster Briton with a time of 59.01 seconds, trailing Gandy, who clocked a time of 58.71 seconds.
Lowe was the 12th fastest qualifier in the heats, finishing in 59.89 seconds.
There are only two places in the Great British team for the butterfly event at the London Olympics, meaning that one of the trio will miss out.
All three will now compete in the semi-finals later today.