Ellie Simmonds underlined why she is one of the stars of the Paralympics as she shocked herself with a new world record in the heats of the SM6 200 metres individual medley at London 2012.
The 17-year-old has already set a new world mark in the S6 400m freestyle en route to a successful defence of her Paralympic title on Saturday.
On Monday morning she produced a blistering freestyle leg to make her rivals appear as if they were treading water to touch in three minutes 06.97 seconds, 1.13secs inside her own world mark from March when she became the first swimmer to set a global record in the Aquatics Centre.
The Swansea-based swimmer was completely taken aback and a second gold medal is a clear possibility on Monday night, and she said: "I wasn't going for a world record, I was actually going for the Paralympic record but I was just going in there to feel the stroke.
"When I walk out the crowd is amazing, that definitely gives me a big buzz. I just can't wait to race tonight. I am quite shocked with that time. When I was at the finish I couldn't actually see what (the time) was, I had to ask someone.
"I'm really pleased with a two-second PB in the heats. It's good to be on top form at the biggest Paralympic Games of my life."
Fellow Briton Natalie Jones was second fastest through in 3mins 16.41secs and although she was just 0.22secs ahead of Verena Schott, it offers real hope of two further British medals.
Jones knows though that all eyes will be on Simmonds and said: "I tried to keep up with Ellie but you can't keep up with someone as amazing as her. She's a once in a lifetime."
Liz Johnson also qualified in seventh to make it three Britons into the final.