Katarina Johnson-Thompson's World Championship medal hopes in tatters after poor high jump

Katarina Johnson-Thompson's World Championship medal hopes were all but dashed in the second event of the heptathlon after a poor high jump.

The devastated 24-year-old collapsed to the mat, head in hands, after a third failure at 1.86 metres.

It left her with a best clearance of just 1.80m from arguably her strongest event, a full 18 centimetres off her personal best.

That equated to a difference of 233 points, a huge and surely insurmountable margin for the home favourite to claw back, especially given the level of competition.

Johnson-Thompson lay in fifth place with 2,053 points after two of the seven events, with Olympic champion and gold medal favourite Nafissatou Thiam out in front on 2,215.

At the same stage of the Rio Olympics, the Briton led the Belgian by 12 points.

Johnson-Thompson was a star-struck 19-year-old at the 2012 Olympics but, after being dubbed Jessica Ennis-Hill's natural heir for so long, is now expected to deliver medals on the big stage.

But Saturday's failure left the Liverpool athlete with an awful sense of deja vu, having seen her medal hopes at the 2015 World Championships in Beijing ended by three no-jumps in the long jump and her Olympic dreams last year crushed by poor throws, a sixth-placed finish reducing her to tears.

Since returning from Brazil she has made drastic changes to revitalise a stuttering career, making the bold move to split with her long-term coach Mike Holmes and leaving her home city of Liverpool to switch to a training base in Montpellier.

A personal best of 6,691 points in Gotzis in May suggested things were looking up, but once again her form deserted her when it mattered most.

And the doubts over the mental strength of a supremely talented athlete will only increase.

Johnson-Thompson's impressive start to the day, clocking 13.33 seconds in the 100m hurdles, became a distant memory after the high jump. It was the second fastest time of her career, just 0.04secs outside the personal best she set earlier this year.

Sophie Hitchon, the Olympic bronze medallist, needed just one effort to book her spot in the hammer final with a throw of 73.05m.

Team-mates Matthew Hudson-Smith and Dwayne Cowan reached the 400m semi-finals with times of 45.31 and 45.39 respectively, but Martyn Rooney's 45.75 saw him go out.

Cowan, 32, was a latecomer to athletics, having had trials at professional football clubs.

"The first day I stepped on the track the coach told me, 'You're not an athlete and you'll never be an athlete'. And look at me now," he said.

Five of the six 400m heats were won in under 45 seconds, with South Africa's Olympic champion and world record holder Wayde van Niekerk strolling the other in 45.27.

His main rival for gold, Botswana's Isaac Makwala, was the fastest qualifier for Sunday's semi-finals in a rapid 44.55.

Ireland's Brian Gregan also made it through.

Asha Philip clocked a season's best 11.14 to reach the 100m semis, along with fellow Britons Daryll Neita (11.15) and Desiree Henry (11.32), the latter being one of the young athletes who lit the Olympic flame at London 2012.

Elliot Giles, Guy Learmonth and Kyle Langford all made it through the heats of the 800m, but Ireland's Mark English crashed out.