Ellie Simmonds was still running on adrenalin as she overcame "killer" fatigue to book a spot in tonight's final of the S6 50 metres freestyle at what has become a second home for the 17-year-old.
The Walsall-born swimmer has already cemented her place as one of the faces of London 2012 and her appearance behind the blocks prompted wild cheers at the Aquatics Centre.
Two titles and two world records in the SM6 200m individual medley and S6 400m freestyle have already come her way although it could well prove troublesome for Simmonds to add the one-length dash to her roll call.
Fifth in Beijing, she clocked 36.45 seconds behind Holland's defending champion Mirjam de Koning-Peper, American Victoria Arlen - second in the 400m - and Tanja Groepper of Germany.
Some think victory is a formality when Simmonds dives into a pool but she was realistic about the challenge she faces to add to her medals.
The Walsall-born swimmer said: "It's going to be a tough race. The 50m free is my fourth best event but it helps develop my 100 free for later on in the week.
"I am really achy this morning from my 200IM: it was a bit of a killer.
"To do that time nearly on my PB and the way I am feeling I am really happy so hopefully I can go out there and do a PB.
"It's going to be really tough to medal."
She admitted she had had little sleep after her exertions last night.
She said: "Not much really but I think I am running on adrenalin at the moment from what I did last night.
"It's really good, it's starting to get quite tiring but I am looking forward to going back now and having a massage and having physio and rest up for tonight's final."
Despite being tired, the Swansea-based swimmer would not consider reducing her programme.
"I train for four events, at major competitions I do four events.
"I like doing all of them, it gets me all excited, I don't like being bored, I don't like sitting around watching.
"It's good to watch the team but I really just want to be competing so today doing the 50 free, it's a splash and dash really.
"I am more of a distance swimmer than a sprinter so to do that time this morning was really good."
While Simmonds commanded the spotlight, there were a number of other performances that bode well for further British medals tonight.
Heather Frederiksen and Hannah Russell were both quickest into their respective finals.
Defending champion Frederiksen produced an emphatic performance in the S8 100m backstroke to head the field by more than four seconds in 1min 17.63secs.
The City of Salford athlete was highly emotional after her silver in the S8 400m freestyle following 12 months of ill-health when she was diagnosed with neuralgic migraines.
When not hospitalised, Frederiksen was often bed-ridden and she had only six weeks' training but the Billinge-born woman is nothing if not gutsy.
She said: "The 100m backstroke is my main event - I was gold medallist in Beijing in it.
"So it was very nerve-wracking coming in but at the end of the day I got out there and gave it a go and I'm going in ranked number one tonight.
"So I'm going to get out there and get in the mix and have a right good go."
Russell has already secured two medals on her Paralympic debut and today she topped the S12 100m freestyle in 1:02.22.
The 16-year-old is composed and eloquent and she was not looking too far ahead this morning.
She said: "I am really, really pleased with that.
"The heats don't really mean anything to be honest.
"In the final that is when everyone really steps their game up and I need to step my game up.
"If I do, I'll hopefully get a chance for a medal."
Stephanie Millward was second into the S9 400m freestyle as she looks to claim her third medal of the Games.
The 30-year-old did not compete in this event in Beijing, where fourth in the 100m backstroke was the closest she came to the podium, but so far in London Millward has a silver and a bronze to her name.
Today, she was seven seconds clear of her nearest rival Ellie Cole in 4:46.00 although Natalie du Toit was 13 seconds ahead of the Briton as she looks for her third successive title.
Millward said: "It felt really good, it was pretty much the perfect morning swim.
"Natalie looked really good and the gold will be tough but I am feeling confident about getting a medal."
Matt Walker was second into the S7 50m freestyle in 28.59 behind American Lantz Lamback as he looks for his fourth consecutive medal in this event.
He said: "A bit disappointed I didn't go a bit faster but hey I am in a middle lane.
"I am going to give it everything I've got tonight, it's my last race here.
"I want a medal desperately - this is not like me, normally I've got a medal now."
Jonathan Fox and Josef Craig are also into the final.
Other British finalists are Oliver Hynd, Thomas Young and Sean Fraser (S8 100m backstroke), James Crisp (S8 400m freestyle) and James Clegg (S7 100m freestyle).
Susie Rodgers seeks her third medal in 24 hours in the S7 50m freestyle.