Eleanor Simmonds, the 13-year-old, became Great Britain's youngest individual Paralympic gold medal-winner with victory in the 100 metres freestyle at the Water Cube yesterday. There was equal drama in the Bird's Nest stadium as Shelley Woods was compelled to give back her silver medal, Britain's first of the games on the track, after a six-wheelchair crash in the 5,000 metres.

Woods, 22, had been off the pace in eighth place in the 11-woman field, but she avoided the carnage at the bell that led to three athletes going to hospital. However, the United States, Switzerland and Australia had their appeals upheld after the medal ceremony. The race will be rerun on Friday.

Simmonds had no such problems, coming from behind to beat Mirjam de Koning-Peper, the 39-year-old Holland swimmer, in 1min 18.75sec.

“I was not expecting that, I can't believe you are calling me a Paralympic champion,” Simmonds, who was born with achondroplasia, or dwarfism, said. “I had a dream about it [the final] last night. But in my dream I only got silver, so I'm very surprised. In the last 25 metres I just got my head down and went for it. I didn't expect it. My main event, the 400 metres, is coming up and I'm really excited.”

Eleven of Simmonds's family will arrive in time to watch that race on Sunday. Joanne Round is Britain's youngest ever Paralympic gold medal-winner after winning the swimming relay at the age of 12 in the Seoul Paralympics 20 years ago.

Simmonds's gold kept Britain in third place in the medals table, with seven golds, one more than Australia, but one fewer than the United States and China.

Dave Roberts, Simmonds's Swansea team-mate, won the 100 metres freestyle, for the third consecutive Games, to secure his eighth Paralympic gold.

Anthony Kappes and Barney Storey, of Britain, won the men's tandem one-kilometre time-trial. Kappes, who is partially sighted, was thrilled to add the Paralympic title to his World Championship and World Cup victories. “We follow the model of the able-bodied lads,” he said. “What they do we try to do.”