Record breakers lay down gauntlet

"This proved that my hard work over the past few months has paid off. I still need to work on many details as I'm not very consistent now. I will try my best to be faster at the worlds," Li added.

"All my setbacks, tears and injuries have forged me and resulted in the new record. From the Tokyo Olympics to the worlds in Abu Dhabi last year until now, all the progress that I have made is thanks to the many people who have supported me, including my coaches, parents, clubs and the nation. I will try my best to deliver better results and repay my supportive fans. I'm looking forward to producing a better me in December in Melbourne."

Li's coach, Mark Schubert, said the only goal at next month's worlds is to win gold but believes an even faster time could be possible.

"We expected a world record for Li, but over two and a half seconds faster than the world record was shocking. Her performances in training over the past few months have been the best that I have ever seen, so I knew she was going to achieve this," said the American.

"We still have a lot of work to do. For a long period, she had only three days' rest. I think she can swim faster in Melbourne. We will do more distance, more speed work. I still think she can be even better. We shall see."

Another swimmer to look out for at the worlds is Tang Qianting after the 18-year-old powered to an Asian-record 1:03.15 in the women's 100m breaststroke on Friday. The following day, she twice lowered the Asian record in the 50m breaststroke, clocking 29.19 in the final.