Jamaican sprint star Shericka Jackson is out of the women's 200 metres in a huge boilover after she slowed down at the end of the heats on Monday morning.
Jackson, who won bronze in the women's 100m final on Saturday night, was kicked out of the event when she was swallowed up by runners behind her after she appeared to casually stroll over the finish line.
There was still 40m to run when she inexplicably began to slow down.
As one of the favourites to win a medal in the 200m, Jackson was noticeably slow out of the blocks and never threatened to win the heat.
Needing to finish top three for automatic qualification in the semi-final on Monday night, Jackson let Italian Daila Kaddari run up alongside her at the finish line when she had been third in the heat.
Both runners hit the line with official times of 22.67 - but officials eventually gave third place to Kaddari by an official time ruling that found Kaddari had edged in front by microseconds.
With the heat being one of the slower of the seven heats run, Jackson also failed to qualify as one of the fastest runners outside the top three finishes of each heat.
Her personal best time in the 200m this year is 21.82 seconds.
Her half-hearted performance came back to bite her immediately - and it was all too much for Channel 7 commentator Bruce McAvaney and former Aussie runner Tamsyn Manou.
"She's not even trying," Manou said.
"Look at her at the back of the field. It's good to have confidence in sport but that's just being a little bit too cocky, you can't run like that."
McAvaney added: "Four one thousandths of a second would have got her through. I can't believe the unprofessional way she went about that race."