Sweden's Therese Alshammar has ignited the world championships trials in Sydney by lowering her own world mark in the non-Olympic 50m butterfly.
The 31-year-old blew away the field in her heat, thrashing Libby Trickett by a full body length in the one-lap dash.
It continues the reigning world champion's love affair with the Sydney Olympic pool, her three Olympic medals from four Games all coming at the 2000 event.
Alshammar stopped the clock at 25.44 seconds to slice 0.02 of a second off the record she set in June 2007.
But she won't have another chance to break it because foreigners are not allowed to compete in semi-finals or finals and there is no B final.
