In the men's 100m backstroke, world record holder Aaron Peirsol was sensationally knocked out in the semi-finals when he managed no better than the ninth-fastest time, while Japan's Junya Koga swam a championship record in 52.39.

Germany's Helge Meeuw and Koga's compatriot Ryosuke Irie followed into the final.

Spain's Aschwin Wildeboer, who swam a championship record in the heats in the morning session, had the fourth-fastest time.

Soni, who swam a championship record in the heats in the women's 100m breaststroke went one better in the semi-finals, when she managed to break Leisel Jones' world record.

Jones' time was 1:05.09, which Soni bettered by .25 seconds, thereby becoming the first swimmer to manage to get under the 1:05 mark in a time of 1:04.84.

She was followed into the finals by Russian Yuliya Efimova and Australian Sarah Katsoulis.

American-born Serbian Milorad Cavic won an unlikely gold medal for the Balkan country as he won the men's 50m butterfly in a time of 22.67, which set a new championship record, beating Rafael Munoz's time of 22.68.

Australian Matthew Targett won the silver medal in a time of 22.73, while the bronze went to Munoz, who was .21 seconds off the pace.

Zueva led the way into the final of the women's 100m backstroke with the world record time of 58.48 in the semi-finals, beating the time set by Briton's Gemma Spofforth in the heats in the morning session.

Monday's final gold medal went to Kukors, who smashed the world record she established on Sunday in the women's 200m individual medley.

Kukors' time of 2:06.15 was nearly a second faster than the 2:07.03 she swam in the semi-finals.

The silver medal went to Australian Stephanie Rice in a time of 2:07.03, while Hungary's Katinka Hosszu won the bronze medal in 2:07.46.