Teenage swimming sensation Ellie Simmonds was tonight crowned queen of the pool as she dramatically defended her Paralympic title and smashed the world record.
Simmonds, 17, had the Aquatics Centre in raptures as she touched home ahead of rival Victoria Arlen in a pulsating race.
She was trailing for much of the tussle but powered home in the final 50 metres, beating the previous world record - previously held by Arlen - by an incredible five seconds.
The build-up to the S6 400m freestyle race was marred by controversy as the American was subjected to a late reclassification ruling.
Simmonds cried tears of joy as she retained the title she won as a 13-year-old in Beijing.
The atmosphere in the Aquatics Centre was electric from the off, with fans on their feet and roaring as she was introduced.
After the race, an emotional and "exhausted" Simmonds choked back tears as she paid tribute to the crowd.
She said: "It was so tough.
"It was so hard on the last 100 and I thought I have to put my head down and I will do it for everyone who has supported me."
She added: "Everyone has been wishing me good luck and I did this for myself, my family and everyone."
She told reporters she drove herself on by thinking of all her supporters
Simmonds' remarkable victory capped a memorable Super Saturday for ParalympicsGB which left Britain in their targeted position of second in the table with a 34-medal haul.
The tally includes nine golds, 14 silvers and 11 bronze medals.
Earlier in the day, Richard Whitehead sent the Olympic Stadium into a frenzy as he powered back from way down the field to take gold in the T24 200m in world record time.
Whitehead, 36, from Nottingham, dedicated the win to his family, including pregnant fiancee Valerie Davies.
"It's all about guts and determination," said Whitehead, a double amputee from birth, who has the words "cometh the hour cometh the man" tattooed on his arm.
"Today I came, I saw, I conquered.
"That was what the two-gun salute was all about - in honour of my hero Chris Hoy."
Seconds after the win, Valerie tweeted: "Love u baby. At finish line! We are all so proud of u! Love val, bump, mum & dad!!! #proudmoment."
Whitehead told reporters: "I came, I saw, I conquered"
Golden couple Sarah and Barney Storey both won golds in their respective events in the Velodrome.
Former swimmer Storey had the crowd roaring from the start as she won her second gold of the Games in the C4/5 500m time-trial.
Sarah Storey was elated at her win
And husband Barney picked up gold as a pilot when he guided Neil Fachie to victory in the tandem one-kilometre time-trial.
Sarah's win came two days after she landed gold in the C5 three-kilometre individual pursuit.
Speaking after today's win, she paid tribute to the "amazing" Velodrome crowd, saying: "It's just incredible. If you move, everyone cheers. It feels like your own family has grown by 6,000 people. It was amazing.
"It's an incredible venue and I feel so lucky to have won in front of these fans."
Natasha Baker became the first to win a gold medal in the equestrian event at Greenwich Park.
The 22-year-old fought back emotion as she triumphed in the Grade II individual championship on her Games debut.
Baker, 22, from Uxbridge in Middlesex, contracted transverse myelitis, an inflammation of the spine which affects the nerve endings, at 14 months.
Boris Johnson thanked ParalympicsGB for delivering the country's second Super Saturday of London 2012 with another stunning medal haul.
He said: "This truly has been Super Saturday for ParalympicsGB, with a stupendous 15 medals won so far and yet more records smashed.
"This tidal wave of talent has got the whole nation cheering and I look forward to yet more inspirational performances in the days to come."
Saturday's ParalympicsGB gold medals were being marked by a spectacular light show on Tower Bridge shortly after 10pm tonight.