Kathleen Baker set a new world record in the women’s 100m backstroke at the US Championships in California on Saturday.

The 21-year-old swam a 58.00 to take a tenth off previous record of 58.10 set by Canadian swimmer Kylie Masse at last year’s World Championships in Budapest.

The foundations of this record-breaking performance were laid in a stunning first 50m, which Baker blitzed in 27.90.

And she needed to be fast. The top three finishers were all well inside 59 seconds, with Olivia Smoliga finishing second in 58.75 and Regan Smith third in 58.83.

“I’ve always been someone to go out fast,” Baker told the Team USA website immediately after her win. “I have a lot of adrenaline when I swim and I get really excited to race.

“Usually I don’t feel that fast until I do the turn and then I’m like, ‘Oh wow that hurt a little bit’, but I wanted to really push it tonight.

“I was looking to see if I won first and then I realized I went 58.0 and I was literally, like, shook. Oh my gosh, I just broke the world record! I’m so happy right now.”

Baker’s new world record took more than half a second off her personal best, and 0.77 seconds off her 2018 best.