The 17-year-old notched a time of 46.96sec to defeat Hungarian Kristóf Milák and Italy’s Alessandro Miressi.

Milák finished in 47.47 before Miressi followed 0.77 later.

Popovici broke the previous world record of 46.91 set by Brazil's César Cielo during the 2009 World Championships at the same venue.

Yohann Ndoye Brouard was on top of the world following the men’s 200m breastroke final that saw him win gold in 1min 55.62sec.

Benedek Kovács, who clocked at 1:56.03, sealed another silver medal for Hungary while Britain’s Luke Greenbank recorded 1:56.15 to finish third.

Sarah Sjöström acquired the women’s 50m backstroke title thanks to a time of 24.96, with France’s Marie Wattel winning silver on 25.33 and The Netherlands’ Maaike de Waard third on 25.62.

The home nation enjoyed a one-two in the women’s 100m breastroke as Benedetta Pilato touched the wall first in 1:05.97 and Lisa Angiolini following in 1:06.34

Ruta Meilutytė obtained bronze for Lithuania, clocking at 1:06.50.

Hungary experienced the same in the women’s 400m individual medley through Viktória Mihályvári-Farkas and Zsuzsanna Jakabos making 4:37.56 and 4:39.79 respectively.

Britain’s Freya Colbert claimed bronze in 4:40.06.

Italy's Gregorio Paltrinieri topped the men’s 800m freestyle podium in 7:40.86 as Germany’s Lukas Märtens clocked at 7:42.65 to win silver with compatriot Lorenzo Galossi taking bronze in 7:43.37.

The women’s 4x100m freestyle saw Britain claim victory with a time of 3:36.47, which was enough to better Sweden’s 3:37.29 and The Netherlands’ 3:37.59.

In the artistic swimming events, Ukraine and Italy triumphed in the women’s duet free and mixed duet free events respectively.

Ukraine scored 94.7333 to defeat Austria and Italy, who made 93.0000 and 91.7000 to take silver and bronze.

Meanwhile, Italy recorded 89.7333, besting Spain’s 84.7667 and Slovakia’s 77.0333.

The competition is due to continue tomorrow.