Adam Peaty smashed the 100m breaststroke world record and became Olympic champion to secure Great Britain’s first gold at Rio.

The 21-year-old powered home in 57.13 seconds to become the first British man to win gold in the pool for 28 years.

Peaty had broken his own world record in the heats on Saturday and repeated the feat, leading throughout and pulling away over the final 50m to win by a huge margin considering the race distance and easily outpace his Saturday time of 57.55.

Peaty was also ending the Great Britain team’s wait for a medal at the Games, and another arrived just a couple of minutes later when Jazz Carlin claimed silver behind the amazing Katie Ledecky of the USA in the women’s 400m freestyle.

Coming into the Games as world, European and Commonwealth champion, Peaty was hot favourite to complete the set and he delivered in style, coming home ahead of Cameron van der Burgh of South Africa and Cody Miller of the United States.

He said: “I can’t even put into words how much that swim meant to me. I put so much effort in to that dive and so much effort in to that back end and that’s what you get.

victory in the 4 x 100m relay.

“Me and Mel [Marshall, coach] thought the best possible race I could do was 57.3 so I have to slap myself to believe I’ve just done a 57.1. It’s absolutely incredible.

“It’s so surreal to get Team GB’s first gold, but this product is seven years of work.”

Ledecky is certain to be a star of the Rio Games and the American then smashed her own world record to win by a long way in three minutes, 56.46 seconds, but Carlin produced a fantastic swim of her own, clocking 4:01.23 to claim second place.

Carlin said: “I’m over the moon. I just wanted to come here and give it absolutely everything. I was in the call room watching Adam and I had goosebumps on the blocks really.