BARCELONA (REUTERS) - Lithuania's teenage Olympic champion Ruta Meilutyte set a world record of 1min 04.35sec in the semi-finals of the women's 100 metres breaststroke at the world swimming championships on Monday.

The 16-year-old, who won gold at the London Olympics last year and is chasing the Baltic nation's first world championship gold, shaved a tenth of a second off the previous mark of 1:04.45 set by American Jessica Hardy in 2009.

Meilutyte, who trains in England, had already gone close to the record in her heat on Monday morning with a time of 1:04.52.

After 50 metres of her semi-final, she was just off the pace but produced a powerful late burst to claim the first world record of the pool competition in Barcelona.

The record had been "one of her dreams" and was more important than winning Tuesday's final but a gold would nonetheless be the "cherry on the cake", she told reporters.

"I'll have a relaxing day tomorrow and save all my energy for the final," she added. "My biggest aim is accomplished now and I'll give it my best shot."