Swedish veteran Sarah Sjostrom surged to her fourth straight world title in the women's 50m butterfly in Budapest on Friday.

In the night's second final, Ben Proud claimed Britain's first gold of the championships as he grabbed victory in the 50m freestyle.

Sjostrom won her race in 24.95sec to edge Frenchwoman Melanie Henique by 0.36sec with China's Zhang Yufei third at 0.37.

She tied the record for most consecutive world titles in the same event, but the record could prove short-lived. American Katie Ledecky was racing the women's 800m freestyle, which she has won four straight times, later in the evening.

Proud exploded from the blocks to take an early lead and held on to win in a time of 21.32, just outside Caeleb Dressel's championship record.

The American, the defending world and Olympic champion, quit the competition on Wednesday.

American Michael Andrew was second on 21.41. Frenchman Maxime Grousset grabbed 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.