Dame Sarah Storey
Dame Sarah Storey claimed a record-breaking 12th gold medal in Rio Getty Images

Dame Sarah Storey has become Great Britain's most successful female Paralympian after winning the 12th gold medal of her career on the opening day in Rio. The 38-year-old cyclist claimed her record-breaking medal in the C5 3,000m individual pursuit final, overtaking teammate Crystal Lane, who took silver, after just 1,375m of the race.

Prior to the final, Storey shared the GB women's record for Paralympic gold medals with Baroness Tanni Grey-Thompson, the former wheelchair racer. As expected, however, she easily defeated her compatriot on the track to move clear of Baroness Tanni on the all-time list.

"Tanni's still a hero to me," said Dame Sarah, who is set to compete in the C4-5 road race, C5 time trial and C4-5 500m time trial in Rio, reports the BBC. "To go quicker than London after having my daughter Louisa is the icing on the cake.

"You can never underestimate anyone on the other side of the track. It's amazing and I don't think it will sink in for a very long time."

Elsewhere on a glittering first day for Team GB in Rio, which featured five golds and 11 medals in total – Steve Bate, along with his pilot Adam Duggleby, and Megan Giglia secured additional cycling golds, while swimmers Ollie Hynd and Bethany Firth also finished first in their finals.

Their success was supplemented by silver and bronze medals for swimmers Harriet Lee and Stephanie Millward respectively. Jessica-Jane Applegate, meanwhile, won bronze behind Firth in the S14 100m backstroke final.

Giglia won Britain's first medal of the day in the C1-3 3,000m and subsequently confessed she was overwhelmed by her achievement, having previously doubted whether she would make it to Rio.

"It hasn't sunk in yet. I wouldn't be here without my teammates, and my back-up team behind me," the 31-year-old athlete, who had a brain haemorrhage and stroke four years ago, told Channel 4.

Megan Giglia
Megan Giglia won Great Britain's first medal in Rio Getty Images

"I didn't think I would make it to Rio and I thought it was a bit ambitious but I wanted to give it a go. Within the British camp, everyone is hyped up and ready to go. I have another three events to go so I will enjoy the races with my legs pedalling as fast as I can."

In the pool, Hynd recorded a world record of four minutes 21.89 seconds to win the S8 400m freestyle final, having won a silver medal at London 2012. "There isn't a day that's gone by where I haven't thought about London and it's all been about putting it right," the Mansfield-born swimmer said after winning gold.

"I knew I needed to go out and do my own race. Although I'm a little bit disappointed not to go quicker, the gold is the most important thing."

Other notable performances from members of Team GB included Jonnie Peacock beginning the defence of his T44 100m title by recording a Paralympic record 10.81 seconds to win his heat, while Alan Oliveira – the double amputee world record holder – failed to even qualify for the final.

Additionally, Britain's Georgina Hermitage equalled her world record in her T37 100m heat – and will be going for gold on Friday (9 September).