Great Britain’s Jessica Ennis-Hill has moved into gold medal position after the first day of the heptathlon with Katarina Johnson-Thompson sitting in fourth.

The athletes are four events into the competition and a see-saw first day leaves the defending champion at the top of the tree.

The 30-year-old currently holds a 72-point lead over Belgian Nafi Thiam, while Akela Jones from Barbados is a further 21 points adrift.

Fellow Brit Johnson-Thompson held a lead going into the evening session but after disappointment in the shot put she has dropped down into fourth.

The 23-year-old was hoping to get through one of her worst events with as little issue as possible but could only throw 11.68metres.

World silver medallist Brianne Thiesen Eaton sits down in sixth and it is Thiam who looks most likely to challenge to two Brits for a medal.

Ennis-Hill, who is priced at 1.30 to win gold, was 184 points ahead going into the second day at London 2012 but will head into Saturday’s disciplines looking over her shoulder.

The Sheffield-born athlete ended the day with a time of 23.49 seconds in the 200m and she admitted it has been very stressful so far.

Ennis-Hill said: “It’s been a mixed day. “l was really happy with my hurdles and high jump.

I was obviously disappointed with my shot put, that was frustrating. “I was a bit down on the 200m but generally happy.

I need to rest up and come back strong tomorrow. I’m trying to enjoy it but it’s very stressful.”