Ledecky set to become first woman to win 12 golds at Worlds

Gold-medal machine Katie Ledecky cruised into the women's 1,500m freestyle final from yesterday's heats at the Fina World Championships to stay on course for an historic 12th gold.

Ledecky clocked the fastest time of 15 minutes and 47.54 seconds - nearly 18 seconds ahead of the field - to maintain her iron grip on the event.

"I feel good. I just wanted to have a controlled easy swim and get a good lane for the final," said Ledecky.

The unstoppable 20-year-old has already picked up two golds on Sunday, winning the 400m title for the third championship in a row, then helping the United States win the 4x100m relay.

That left her level with Missy Franklin on a record 11 gold medals at the world championships. Ledecky is on course to win her third title - of a possible six in Budapest, Hungary - in tonight's 1,500m final which would make her the first woman to win 12 world championships golds.

Meanwhile, in the men's 100m breaststroke final last night, Britain's Adam Peaty retained his title with a new championship record of 57.47sec.

Kevin Cordes of the United States finished second at 1.32sec back with Russia's Kirill Prigoda third at 1.58.

Peaty had targeted his own world record of 57.13sec, set when he won the Olympic title last year in Rio de Janeiro, but came up short in his bid.

Nevertheless the 22-year-old was delighted to defend the world title he first won in Kazan two years ago.

"A lot of hard work goes into competing and the crowd were amazing. I want to thank everyone out there," Peatty said after his win.

Following Peaty's victory, Sarah Sjostrom of Sweden won the women's 100m butterfly gold for the fourth time in her career.

The 23-year-old clocked 55.53sec, a new championship record, just 0.05sec from the world record she set at the Rio Olympics.

Australia's Emma McKeon took silver at 0.65sec back with Kelsi Worrell taking bronze at 0.84sec.

Fresh from winning the men's 400m freestyle on Sunday, China's Sun Yang was the fastest through the 200m freestyle heats into last night's semis, but admitted feeling jaded.

"I was a little tired, I didn't do my best in the heat, but I didn't have to," said the 25-year-old Chinese star.

Despite his fatigue, Sun clocked 1:45.78 with Britain's James Guy, the defending world champion, just 0.44sec back.

Katinka Hosszu, the Olympic champion, was the second-fastest qualifier for last night's women's 100m backstroke semi-finals, just 0.18sec behind Canada's Kylie Masse.

Hosszu refused to speak to reporters after her heat.