Kliment Kolesnikov set a new 50m backstroke world record and also won a relay gold in Budapest today ©Getty Images

Russia's Kliment Kolesnikov set a new world record in the 50 metres backstroke and then won a relay gold medal as pool-based swimming races began in fast fashion at the European Aquatics Championships in Budapest.

Kolesnikov stopped the clock at 23.93sec in the 50m backstroke, becoming the first man to break the 24-second barrier, and then helped Russia win the men's 4x100m freestyle relay.

Teaming up with Andrei Minakov, Aleksandr Shchegolev and Vladislav Grinev, the winning time was 3min 10.41sec - a championship record.

Britain finished second and Italy third.

Kolesnikov is the red-hot favourite for the 50m backstroke final, scheduled for tomorrow in the Hungarian capital's Duna Arena.

Britain tasted victory in the women's 4x100m freestyle relay, with the team of Freya Anderson, Abbie Wood, Lucy Hope and Anna Hopkin narrowly beating the Dutch by 0.12sec.

France won the bronze medal.

Olympic 400m medley champion Katinka Hosszú was more than two seconds clear of the field in the final ©Getty Images
Olympic 400m medley champion Katinka Hosszú was more than two seconds clear of the field in the final ©Getty Images

There was double joy for the host nation in the women's 400m medley as triple Olympic champion Katinka Hosszú won the gold medal and Viktoria Mihalyvari-Farkas was runner-up, tied for second place with Britain's Aimee Willmott.

The day's other gold medal went to Russia's Martin Malyutin in the men's 400m freestyle.

Malyutin overtook Austria's Felix Aubock on the last length, with Aubock going on to finish second ahead of Lithuania’s Danas Rapysis.

The European Swimming League's marquee event continues tomorrow.