Ellie Simmonds put a disrupted build-up to her final day at the Aquatics Centre behind her as she launched her bid for a fourth medal of the Paralympics in the S6 100 metres freestyle.
The 17-year-old has already claimed two golds and one bronze medal at the Aquatics Centre and this morning she went through second fastest behind Victoria Arlen in one minute 16.68 seconds.
The American equalled her own world record of 1min 14.74secs as she headed the field by 1.94secs.
Simmonds' task has been aided by the withdrawal of S6 50m free champion Mirjam de Koning-Peper but she was just glad to have negotiated this morning's heats.
Simmonds said: "I had a rubbish lead-up to this one: I couldn't sleep at all last night. I've been quite emotional, I don't know why.
"But I am enjoying it, I think that is what I am going to get out of tonight - enjoy today and it's the last day. I've had the best time of my life so far so I am just enjoying it all now."
The Swansea-based swimmer added: "It's the end but I've had so many amazing swims and stuff but I am quite an emotional person so it comes out.
"I think it is going to be a really tough race. It's going to be so tough but I am just going to go out there and enjoy myself.
"I've got two gold medals, I've got world records, got a bronze medal. Amazing achievement - I am just going to go out and enjoy it."
Arlen, second behind Simmonds in the 400m freestyle, added: "This is my last race and I'm fired up and ready to go. I love the 100 and I'm just going to go all out in the final."