Sydney (AP) Twice in two nights: Eamon Sullivan broke his own 24-hour-old world record in the 50-metre freestyle Friday at the Australian swim championships and Olympic trials.

It was the fourth time in the past six weeks that the record has been broken after Russian Alexander Popov's record had stood for nearly eight years. The 22-year-old Sullivan has improved on it for the third time in that span.

Sullivan clocked a time of 21.28 seconds in the final at the Sydney Olympic Park Aquatic Centre, where he had lowered the mark to 21.41 in the 50 free semifinals Thursday.

That mark had broken France's Alain Bernard time of 21.50 set at the European championships in Eindhoven, Netherlands last weekend.