The teenage phenomenon overhauled Poland's defending champion Radoslaw Kawecki to win the 200 metres backstroke final at the Royal Arena in the Danish capital.

Kolesnikov produced a blistering finish to triumph in 1min 48.02 seconds, enough for victory by 0.46 and to establish the first world junior record in the event.

He also broke the championship record of 1:48.33 set by Kawecki two years ago.

Lithuania’s Danas Rapsys took bronze in a time of 1:49.06.

Kolesnikov then set a second record, and won a second gold medal, with a rapid opening lap of 21.24 in 4x50m freestyle relay.

He combined with Vladimir Morozov, Sergei Fesikov and Mikhail Vekovishchev for a winning time of 1:23.32.

Italy’s Luca Dotto, Lorenzo Zazzeri, Alessandro Miressi and Marco Orsi took silver in 1:23.67.

Poland's Pawel Juraszek, Filip Wypych, Jakub Ksiazek and Konrad Czerniak finished third in 1:24.44.

Hungary's Katinka Hosszú was among other winners on the opening day of competition.

She clocked 4:24.78 to win the women's 400m individual medley and duly claim her 11th career gold medal in the continental shortcourse event.

In the absence of her Spanish rival Mireia Belmonte - who remains the world record holder - France took a distant silver and bronze.

Lara Grangeon placed second in 4:28.77 while Fantine Lesaffre was third in 4:30.68.

Russia's superb opening day also included a win for Aleksandr Krasnykh in the men's 400m freestyle.

He triumphed in 3:35.51 to defeat Hungary's Peter Bernek, second in 3:37.14, and Henrik Christiansen in Norway, third in 3:38.63.

Lithuania's Ruta Meilutyte won the women's 50m breaststroke in 29.36.

Finland's Jenna Laukkanen was second in 29.54 while bronze was taken by Sophie Hansson of Sweden in 29.77.

Fabio Scozzoli of Italy won the corresponding men's event in 25.62.

He edged out Russia's Kirill Prigoda, who was second in 25.68, while Britain's Adam Peaty suffered a rare defeat as he could only manage third in 25.70.