Australia's Sally Pearson overcame last week's 100 metres heartbreak to win the hurdles event over the same distance on Monday, collapsing on the track in tears after her golden run.

Pearson was distraught last Thursday when she was disqualified for a false start three hours after crossing the line first in the women's sprint.

There was to be no false start for her on Monday, though, and she quickly took the lead before finishing in 12.67 seconds with a huge beam on her face.

"It was a very difficult week. I tried my best to keep training and keep my focus. Today I was probably the last one out of the blocks," the 24-year-old said after her win.

With the Canadian and Jamaican teams leaving some of their best athletes at home, the field was open for Pearson, the Beijing Olympic silver medallist in the event.

She was also keen to erase the memories of the 2006 Melbourne Games, where she fell in the final after clipping a hurdle to blow her medal chances.

Nigeria's Osayemi Oludamola, who was handed the 100m gold after Pearson's disqualification, tested positive for a banned substance and is almost certain to lose the medal if the B sample confirms the original.

"I don't know how many months she would be out or what her punishment should be. I just know I run drug free - I really do," Pearson had said after her victory lap.