Budapest (AFP) - Swedish veteran Sarah Sjostrom surged to her fourth straight world title in the women's 50m butterfly in Budapest on Friday.
Local hero Kristof Milak sparked delirium in the Duna Arena when he grabbed the 100m butterfly title, his second of the week.
Ben Proud claimed Britain's first gold of the championships as he grabbed victory in the 50m freestyle.
Australian Kaylee McKeown won the women's 200m backstroke for a first world title to go with three Olympic golds.
Sjostrom won her race in 24.95sec to edge Frenchwoman Melanie Henique by 0.36sec with China's Zhang Yufei third at 0.37.
"It's amazing to win this race, to keep myself on the top is very hard," said Sjostrom.
"That was a tough race.I had a lot of pressure on myself because of my past successes."
Milak, who had already won the 200m butterfly title, provoked delirium in what he calls "my pool" as he finally won gold in the 100m.Caeleb Dressel, the reigning world and Olympic champion, pulled out of the competition on Wednesday.
Milak won in 50.14sec, a comfortable 0.80sec ahead of Naoki Mizunuma of Japan, with Canadian Joshua Liendo a further three hundredths of a second back in third.
"Obviously, I'm not satisfied with the time as I swam exactly the same time as in the semis.But I won the gold and that's the most important now," said Milak.
"I'm so proud to be Hungarian and I'm overjoyed that here in the arena 4,000 people were cheering for me.I hope, in front of the TVs and all around the world, all 15 million Magyars gave me their support."
'Great race'
In another event where Dressel had been the reigning champion, Proud exploded from the blocks to take an early lead and held on to win in a time of 21.32.
American Michael Andrew was second on 21.41.Frenchman Maxime Grousset grabbed third.
"Great race, great field, great fans and great job!This is a strong result," said Proud."Before I came here, if someone said I'd go home as a world champion, I'd have laughed out loud."
McKeown chased American Phoebe Bacon down in the last lap to win at the touch by just 0.04sec.
Another American, Rhyan White, was a distant 1.88sec back in third.
Sjostrom had a quick turnaround as the semi-finals in the 50m freestyle began 25 minutes after the butterfly final.
The Swede, the world record holder, won the second heat and qualified for the final second to Pole Katarzyna Wasick.
Sjostrom then climbed out of the water and onto the podium for the butterfly victory ceremony and her 19th overall world championship medal, dating back to 2009.
