Great Britain's Adam Peaty has won his first gold medal at a World Championships by clinching the title in his last stroke in Kazan.
The 20-year-old, who holds the world record at 57.92 seconds, was half a metre behind South Africa's Cameron van der Burgh at the start of the race.
However, the four-time European champion showed his strength in the final 25-metre stretch to touch the wall in 58.52s, just ahead of Van der Burgh, while GB's Ross Murdoch claimed bronze in 59.09 seconds, which is a Scottish record.
Britain now have three medals to their name following James Guy's triumph in the 400m freestyle final on day one of the meet.