World champion Reece Dunn had to settle for silver in the S14 100m butterfly (Picture: Reuters)

Paralympic debutants Reece Dunn and Toni Shaw claimed medals for Great Britain on day one of the swimming at the Tokyo Aquatics Centre.

World champion Dunn had to settle for silver in the S14 100m butterfly as Brazilian Gabriel Bandeira pipped him to first place with a Paralympic record of 54.76.

Earlier, 18-year-old Shaw won ParalympicsGB’s first medal of the Games in the pool, clinching bronze in S9 400m freestyle with a lifetime best of 4:39.32.Plymouth Leander swimmer Dunn – the world record holder – finished 0.36 seconds adrift of Bandeira after falling short as he battled to overhaul his rival during a hard-fought second length.

The 25-year-old had underlined his gold credentials as the fastest qualifier, setting a Paralympic record of 55.99, which he and, crucially, Bandeira then subsequently broke in the final.

‘I’m a little bit disappointed with my finish, I lost it there, but still happy nonetheless,’ he told Channel 4.

Toni Shaw won ronze medal won in the Women’s 400m Freestyle S9 (Picture: PA)

‘I knew it was going to be a tough race coming in and it was going to go down to the last five metres and he obviously beat me to it.’