Ellen Gandy broke the British record in the 100m butterfly to book her place in the Olympics.
Halsall joins winner of trials in London as Lowe misses out
Ellen Gandy won the 100 metres butterfly with a new British record as she booked her place in the Olympics at the trials at the Aquatics Centre.
Gandy pipped Fran Halsall in the final metres to touch in 57.25 seconds, cutting 0.15secs off Halsall's 2010 mark.
Halsall was second in 57.56, with both women's times inside that required by British Swimming to qualify for the GB team.
Jemma Lowe, who reached both butterfly finals at last year's World Championships, was third in a final where a world-class athlete was destined to miss out.
Gandy last year became the first British woman to win a global butterfly medal when she was second in the 200m at the World Championships in Shanghai.
"It's the greatest feeling ever," said the Melbourne-based swimmer. "All I've wanted to do for the last four years is be able to say 'I'm going to the London Olympic Games' and now I can say it. I am just over the moon.
"The time was a bit irrelevant to me because I just wanted to make the team. I'm thrilled I got the British record. I think Fran was beating me most of the way but I think my 200m training helped me down the last 25m."
Disappointed
Of Lowe, Gandy said: "It is devastating when the third person gets left behind and unfortunately it was Jemma, but she has the 200m later in the week."
Halsall was happy to have booked her place but disappointed with her performance.
"Everything I've done in training has been going so well and it indicated I'd swim a lot faster than I did so it's just going back and analysing that," she said.
"But I'm on the team now and that is all that matters at this moment in time. It's faster than I've ever done at this time of year before."
Lowe said: "Obviously I am really disappointed. One of us had to come third and it was me today. I gave it my best shot but it wasn't good enough but I've got another shot in the 200."
All three were part of the Smart Track programme, a group of girls aged 12-14 identified by former national performance director Bill Sweetenham along with John Atkinson and taken to intensive training centres in remote areas of the world.
All three swimmers made their Olympic debuts in Beijing four years ago with Gandy the baby of the GB team.
Just four years on, the trio have made their mark on the global stage. Both Gandy and Halsall have claimed world silvers as well as assorted European and Commonwealth medals.
Lowe reached both finals at last year's World Championships, a year after taking Commonwealth bronze.
Robbie Renwick heads the field into the 200m freestyle final (1:47.25) with Sophie Allen fastest into the women's 100m breaststroke (1:08.44).
