The 17-year-old clocked a time of 1 min 53.87sec in tonight's finals at Indiana University Natatorium, obliterating the previous record of 1:56.42 set by the United States’ Andrew Seliskar at the 2013 FINA World Junior Championships in Dubai.

It fell short, however, of the world junior record time of 1:53.79 he set at the European Junior Championships in Netanya in Israel earlier this year.

Milák, who won the gold medal in the 100m butterfly and bronze in the 50m butterfly earlier in the meet, dominated his competition with Japan's Yuya Sakamoto a distant second in 1:57.05.

Bulgaria’s Antani Ivanov won his first medal of the Championships and the first for his country, registering a time of 1:57.54 to earn a bronze.

Among the other individual male winners today was Russia’s Ivan Girev, who won the 100m freestyle in a Championship record time of 48.33.

Girev had already set a world junior record in the 200m freestyle earlier in the meet.

Hungary’s Nándor Németh was second to Girev in the 200m and won a second silver medal in the 100m event tonight with a time of 48.95.

The US’s Matthew Willenbring was 0.84 seconds off the pace for the bronze medal.

Also tasting victory today in men’s competition were Spain’s Hugo Gonzalez and Italy’s Nicolo Martinenghi, the winners of the 200m backstroke and 50m breaststroke events respectively. 

Gonzalez set a Championship record of 1:56.69 to win his third gold medal of the meet.

He also won the 100m backstroke and the 400m individual medley earlier in the meet, two victories which also came in Championship record times.

The Spaniard was 1.18 seconds faster than silver medallist Carson Foster of the US tonight.

Russia’s Nikita Tretyakov finished 2.03 seconds behind Gonzalez to collect the bronze medal.

In the 50m breaststroke, Martinenghi led an Italian one-two ahead of Alessandro Pinzuti.

Martinenghi finished in a time of 27.10 to beat his compatriot by 0.09 seconds.

Their performances ended the hopes of the US’s Michael Andrew of a clean sweep of the four strokes’ 50m titles.

Andrew's time of 27.39 was 0.29 seconds slower than that of Martinenghi.

The men's 1,500m freestyle event saw the US's Andrew Abruzzo and Michael Brinegar deliver the second one-two finish of the evening.

Abruzzo, the 400m and 800m freestyle gold medallist, posted a time of 15:06.48 to finish 2.52 seconds ahead of his team-mate. 

Russia's Iaroslav Potapov clocked 15:09.18 for the bronze medal.

The first gold medal of the final day went to the US’s Zoe Bartel, who won the women’s 200m breaststroke in 2:25.68.

American team-mate Ella Nelson finished 1.36 seconds behind to secure the silver medal.

Great Britain’s Annabel Guye-Johnson was 1.74 seconds back in the bronze medal position.

There were also a number of Championship records set in women’s events, including the 100m butterfly which Japan’s Rikako Ikee won in 57.25.

Her time improved on the mark of 58.11 she set yesterday.

Canada’s Rebecca Smith had to settle for the silver medal, 0.82 seconds behind.

Japan's Suzuka Hasegawa was 1.35 seconds back in claiming the bronze medal.

Ikee also improved her Championship record from yesterday in the 50m freestyle, clocking 24.59.  

It bettered the time of 24.74 she set 24 hours earlier, but fell short of her world junior record which stands at 24.48.

US’s Grace Ariola finished 0.23 seconds behind today to capture the silver medal.

Japan’s Sayuki Ouchi claimed the bronze medal after finishing 0.48 seconds off the pace.

In the women’s 200m freestyle, Canada’s Taylor Ruck triumphed in a Championship record time of 1:57.08.

It sliced 0.79 seconds from her winning time set at the 2015 FINA World Junior Championships in Singapore.

Hungary’s Ajna Késely was just 0.02 seconds behind in the runners-up spot.

Russia’s Irina Krivonogova came third in 1:58.51.

The men’s and women’s 4x100m medley relays were also held today with the US winning the former and Canada the latter.

In the men’s event, the American quartet of Drew Kibler, Reece Whitley, Cody Bybee and Willenbring won in a world junior record time of 3:36.15.

Russia, who set the previous mark of 3:36.44 in triumphing at the 2015 FINA World Junior Championships, finished 0.15 seconds behind.

Italy were 0.29 seconds back in third.

There was also a world junior record in the women’s event as Canada’s Jade Hannah, Faith Knelson, Penny Oleksiak and Ruck triumphed in 3:58.38,

The US finished second in 3:59.19, while Japan came third in 3:59.97.