Teenager Katie Ledecky admitted exceeding her own expectations after breaking her second world record and winning her fourth gold in the women's 800m freestyle at swimming's world championships on Saturday.
Having already won the 400m gold and broken the 1500m world record in winning Tuesday's final, the 16-year-old USA long-distance star completed the set in the freestyle events with a new 800m world record of 8min 13.86sec in Barcelona.
In her wake, Denmark's Lotte Friis, who had led for the first 650 metres, finished at 2.46sec back and New Zealand's Lauren Boyle took bronze at 4.72 adrift in a new Oceania record.
Ledecky's Barcelona tally includes the 400, 800 and 1500m freestyle golds plus the 4x200m freestyle relay victory with the USA team.
"I am thrilled, I exceeded my expectations for the year," said Ledecky, as three world records fell in Barcelona on Saturday to make it six in total -- all by women.
"The goal I set at the beginning of the year was three medals and one world record: now I have four golds and two world records so I couldn't be happier."
The 800m final mirrored Tuesday's 1500m final, when both Ledecky and Friis went under the previous world record, with the American imposing her authority in the closing stages after Friis had charged out to an early lead.
"I just carried my momentum from earlier in the week and was able to lay it all out tonight in my last race," said Ledecky, who took 0.24sec off Briton Rebecca Addlington's record from the 2008 Beijing Olympics.
"I knew it was going to be a tough race and I knew Lotte was going to be right in there so I had to patient up front and then try to break away in the last 200m.
"I just had to stay patient and let Lotte swim her own race. She is tough competitor and a lot of fun to go up against."
Friis, who won the event at the 2011 world championships, had nothing but praise for the new champion.
"I think maybe she is going to turn out to be one of the greatest swimmers of all time," said the 25-year-old of Ledecky.
"The plan was to go out a little bit strong, to get as big a gap as possible and then see what Katie was going to do."
Having finished fifth in the Olympic final, Friis said she was happy with her second silver in Barcelona.
