Perri Shakes-Drayton's bid for a first global outdoor medal was yet again derailed by injury as bad luck struck in the 400 metres final at the World Championships.
The Londoner, a strong medal contender, was taken for an ultrasound scan on her left knee straight after the race at Moscow's Luzhniki Stadium.
She finished it in seventh place after a run in which she lost her rhythm entirely, hitting hurdles and abandoning her stride pattern before slowing down at the finish in clear distress.
The 24-year-old revealed she felt the knee complaint after the very first hurdle, but her problems only became evident around the 200m mark.
Her time of 56.25 seconds was more than two seconds down on her semi-final time and more than two-and-a-half seconds slower than her personal best set last month.
Indeed, she has only twice run slower since the start of 2011 and those were both in heats at the UK Championships when she was taking it easy.
She said: "It was going all right until the first hurdle, and after the first hurdle my knee just felt funny.
"It's not the way I would have liked to have finished. It was going so well, leading the heats and the semi.
"But after the first bend I was just going back and back and back. So now I have to go and sort out this knee, but I don't know if I'll actually be in the relay now.
"I don't really know what happened. I was hitting hurdles because of the knee afterwards, but I just don't know. I need to speak to the doctor and to my coach (Chris Zah), but I didn't want it to finish like this.
"It wasn't because of the rounds as I was feeling okay. But these things happen."