Tunisia's Ahmed Hafnaoui won the men's 800m freestyle title at swimming's world championships in Fukuoka, Japan, on Wednesday.
Hafnaoui touched the wall first in a time of seven minutes and 37.00 seconds, ahead of Australia's Sam Short on 7:37.76 and American Bobby Finke on 7:38.67.
Hafnaoui, Short and Germany's Lukas Martens were neck-and-neck for almost the entire race until Hafnaoui pulled away over the home straight.
Hafnaoui had earlier taken silver behind Short in the 400m freestyle on the competition's opening night. He therefore earned sweet revenge for the earlier miss.
"My last race, the 400, I just keep it in mind and try to go faster in the 800 and take the gold," Hafnaoui said.
Hafnaoui is the reigning Olympic 400m freestyle champion. Finke, who came into the race as the Olympic and world 800m champion, came through at the end to overtake Martens.
Meanwhile, Australia's Mollie O'Callaghan set a blistering pace to break the world record in the women's 200m freestyle, capturing the gold medal with a time of one minute, 52.85 seconds at the swimming championships.
O'Callaghan broke the performance-enhancing bodysuit era mark of 1:52.98 set by Italian Federica Pellegrini at the 2009 worlds in Rome, and was 0.16 seconds ahead of silver medallist Ariarne Titmus of Australia.
Summer McIntosh of Canada took the bronze.
"I'm just really shook at the moment because coming into this I did have an injury and I was just expecting to have fun," O'Callaghan said.
"I was going to be really happy. To come away with a world record is just amazing."
Britain's triple Olympic champion Adam Peaty is skipping the meet for mental health reasons after also missing the last edition with a fractured bone in his foot.
His absence is a blow to Britain's hopes of swelling their gold medal tally after Matthew Richards opened their account by leading a one-two in the men's 200m freestyle on Tuesday.