AUSTRALIA'S world champion Sally Pearson suddenly has a major hurdle in her path ahead of the London Olympics.
The winner of 32 of her previous 33 races, including last year's world championship, Pearson was distraught after suffering a shock loss to American Kellie Wells in the finals of the 100m hurdles at a Diamond League meet in London.
Earlier in the day the Queenslander had beaten Wells by .01secs in her heat.
But in the final it was the American who took gold in 12.57secs, well outside the 12.40secs Pearson had recorded in winning in Paris last week.
It was left to her long-time coach Sharon Hannon to try to play down the significance of the loss, which may have been influenced by a slight back injury Pearson picked up when she slipped and fell warming up for her heat.
"I'm as disappointed as Sally is ... pretty gutted," Hannon said. "Certainly in the 100m hurdles it's fraught with danger. A lot of things can go wrong."
Hannon said the final preparations for London would not change despite the shock loss.
She also said Pearson's main challengers for gold may not have even been in the field on Saturday night, mentioning the likes of two other Americans, Dawn Harper and Lolo Jones
"She's been a little nervous going into the last couple of races. There is a lot of expectation on how she's going to perform," Hannon said. "But we've got the next couple of weeks set down pretty much pat. I know what she's going to be doing ... we'll get on with it."
While losing was a new and unwanted feeling for Pearson who has set her target on a first Olympic gold medal, it was a case of deja vu for defending Olympic pole vault champion Steve Hooker.
Suffering a severe case of the yips in recent months, Hooker was again unable to get off the ground in three attempts at 5.40m, well short of the qualifying height of 5.72m he has managed just once this year.
One man still on track for London after the Diamond League meet is long jumper Mitchell Watt.
He won his event with a season's best leap of 8.28m, one centimetre ahead of what he produced to win in Paris the previous week.
"Obviously the Olympics is a massive goal, but I want to win the Diamond League as well," Watt said.
Meanwhile Victorian Collis Birmingham set a new personal best of 13:09.57 in the 5000m to finish second behind Olympic favourite and world champion Mo Farah. Craig Mottram finished seventh and Ben St Lawrence ninth.