Kazan - Britain's Adam Peaty completed the double of world breaststroke titles on Wednesday after adding the 50m title to his 100m crown at Kazan's world swimming championships.
The 20-year-old, who set the 50m world record of 26.42 seconds in Tuesday's semi-final, clocked 26.51 in the final with South Africa's Cameron van der Burgh, the 2013 world champion, taking silver, 0.15 seconds back (26.66).
Kevin Cordes of the USA earned bronze at 0.35 seconds back (26.86).
"That was really good. I missed a couple of strokes, but I just stayed on top of the water," said Peaty.
"It was just a race to touch the wall first and thankfully it was my day.
"I got the world record yesterday and secured the title today - I couldn't really ask for more."
Peaty, the Commonwealth champion, has made a stunning world championship debut in Kazan as he claimed Britain's second gold on Wednesday after Gary Hunt's win earlier in the men's high-diving competition.
Peaty has matched David Wilkie's double - the Scotsman won the 100 and 200m breaststroke titles at the 1975 world championships.
He will be bidding for a third title in Kazan when the 200m breaststroke heats start on Thursday with the final on Friday night.
Having beaten Van der Burgh on the wall in the 100m final, Peaty again came out on top ahead of his South African rival over the sprint distance.
But Van der Burgh was delighted to pick up his fifth consecutive worlds medal in this event - only US star Michael Phelps has picked up more, with six in the 100m butterfly between 2001-11.
"It's just nice to be consistent and always up with the best in the world. I am very honoured and privileged," said Van der Burgh, who is relishing defending his 100m Olympic title in Rio next year.
"I think Phelps is the only other one to get five consecutive medals.
"I think I am the type of swimmer when I come into a competition I have one big swim in me and I think I always try and use it up on the 100m.
"That's the main goal for me, the Olympic Games."
Van der Burgh said he had sympathy for compatriot Chad le Clos after the Olympic champion had earlier lost his world crown to Hungary's Laszlo Cseh in the men's 200m butterfly final.
"Tonight wasn't South Africa's night with Chad getting silver and me getting silver, so we'll take silver this year and we'll kick on next year," said Van der Burgh.
"So it's a lot of motivation, yeah."