Jessica Ennis recovered emphatically from a slow start to head into the second day of the heptathlon in pole position to defend her world title.
After a disappointing morning which left the 25-year-old trailing American Hyleas Fountain after two events, Ennis produced a personal best in the shot put and an impressive 200 metres run into a strong head wind to move into her customary gold medal position.
It left the Sheffield athlete 151 points clear of the field and just two worse off than at the same stage when she won the European Championships in Barcelona last year.
Ennis, who has become accustomed to leading from start to finish as she did at the World Championships in Berlin two years ago and also in Barcelona, had been 41 points adrift of Olympic silver medallist Fountain after the 100m hurdles and high jump, the Briton’s two strongest events.
But she showed she was in no mood to relinquish her crown with a mightily impressive performance in the shot.
Ennis threw 14.67m with her first attempt, with her other two throws also further than she had previously managed outdoors.
She followed that up with 23.27 seconds in the 200m, comfortably the quickest in the field, to move onto 4078 points, with Russia’s Tatyana Chernova her closest challenger.
“It’s been a stressful day,” said Ennis, who only had a 110-point lead after the opening day in Barcelona.
“I knew it was going to be tough, but it’s been really hard today.
“The hurdles did not start well and I did not get the time I wanted and the high jump was not there today. I was very frustrated after the first two events.
“I was nervous before the shot and just wanted to get the points back that I lost. I’m really happy to throw that PB. I knew I could throw far, but had to stay calm and believe I could do it.
“But it’s going to be tough tomorrow, these girls have got strong second days so I have to make sure I am completely on it.”
Ennis clocked 12.94 seconds in a far from smooth run over the hurdles, albeit pipped to victory by only 0.01secs, before managing only 1.86m in the high jump, way down on her personal best and British record of 1.95m.
“I hit two or three hurdles and they are hard, they don’t give at all. I have a massive bruise on my knee but it will be all right tomorrow,” she said. “I could say it affected my high jump but I was not aware of it. I just didn’t have the ping I normally do.”
Those two performances left her in the unusual position of having ground to make up rather than defend.
“It’s a position I am not used to being in,” she added. “I felt frustrated with myself. I wanted to make it right and get back in first position.”
Fountain was third overall, 191 points behind Ennis, with Olympic champion Nataliya Dobrynska fourth, 19 further back. Ennis’s team-mate Louise Hazel was 16th.
1 J Ennis (GB) 4078 pts
2 T Chernova (Rus) 3927
3 H Fountain (US) 3887
4 N Dobrynska (Ukr) 3868
5 K Tyminska (Pol) 3843