Olympic champion Caeleb Dressel set two new short course world records in the men’s 100m butterfly and 50m freestyle events at the International Swimming League finals in Budapest, becoming the first person in history to dip under 48 seconds in the butterfly event.

The American pushed previous butterfly world record holder Chad Le Clos into second and lowered the old record of 48.08 seconds to 47.78. Then, 40 minutes later, Dressel returned to reduce his 50m free world record time from 20.24secs to 20.16.

“It was a really exciting day and I’m so pleased with the times,” Dressel told BBC Sport. “It’s like an amusement park for swimmers and I’m loving it at the ISL this season, but we want to win this as a team – that’s the end goal.”

Dressel’s efforts helped his franchise Cali Condors to a first-day lead of 27.5 points over defending champions Energy Standard, with UK team London Roar third and LA Current fourth.

In his third swim of the day, Dressel missed the 100m freestyle world record by 0.26 seconds while swimming the first leg of the men’s 4x100m freestyle relay, but he will have another chance to beat that mark on day two when he competes in the individual event.

The Cali Condors women’s team set a new world record time of three minutes 44.52 seconds in the 4x100m medley relay, which unlike other ISL relay records, should be ratified as all four women are from the same nation – the USA.

Meanwhile, Energy Standard’s Kliment Kolesnikov set a new world record of 48.58secs for the 100m backstroke while swimming the lead-off leg in their men’s 4x100m medley relay win.

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