Rikke Pedersen, 24, clocked two minutes 19.11 seconds to beat the previous mark of 2:19.59 set by American Rebecca Soni at the Olympic Games in London last year.
Rediff.com takes a look at those swimmers who achieved the double without much trouble.
Nathan Adrian took out the Missile by a fingertip. Daniel Gyurta and Rebecca Soni took down two more world records at the pool.
American swimmer Rebecca Soni smashed the world record in winning the 200 metres breaststroke at the Beijing Olympics on Friday, two years after having heart surgery. The softly-spoken swimmer, who captured the silver in the 100 breaststroke after being a late replacement for Jessica Hardy, who had failed a doping test, made light of her astonishing progress since the surgery.
Olympic champion Ruta Meilutyte of Lithuania set a European and world championship record in the heats for the 100 metres breaststroke in Barcelona on Monday.