Jessica Ennis looks certain to lose her heptathlon title

Jessica Ennis, British athletics' golden girl, looked set to miss out on gold at the world championships in Daegu today, disrupting her preparations for the Olympic Games next year in London.

With just one event in the heptathlon to go - the 800m - the 25-year- old from Sheffield found herself in silver medal position, 133 points behind leader Tatyana Chernova of Russia.

To make up the difference between the two athletes, Ennis would need to run the 800m - scheduled to take place at midday, UK time - nine seconds quicker than her rival.

On personal bests, the Russian is two seconds faster at the distance. So Ennis was left this morning needing to either run a stormer or unsportingly hope that Chernova fell or got held up in the field.

Ennis' overnight lead of 151 points after strong first-day performances in the shot put and 200m was always going to be tested by the Russian, who has far superior times and distances in the second day events.

But a good leap in the long jump for the Brit - she matched her personal best of 6.51m, just 10cm behind Chernova - meant that Ennis still held a lead of 118 points going into the sixth event, the javelin.

The Russian sent her second throw sailing out to 52.95m, a season's best performance, and with Ennis unable to improve on a disappointing effort of 39.95m Chernova made up 251 points to take a commanding lead.

Barring a miraculous two-lap performance, Ennis now relinquishes the world title that she won in Berlin in 2009 - and Chernova serves notice that home advantage will count for nothing in next year's London Olympics.

Great Britain's women's team will leave South Korea disappointed. As well as Ennis losing her title, the reigning Olympic 400m Champion, Christine Ohuruogu, was disqualified from heats in her event for false starting.

The British head coach Charles van Commenee had set a target of seven medals of any colour across the world championships. The team still appears to be on course for with three in the bag already, but they will have hoped to do better. ·