Katarina Johnson-Thompson needs to produce the 800metre performance of her life to have aspirations to win Olympic heptathlon gold on Friday night.

There had been question marks over Johnson-Thompson's form and fitness coming into Paris after withdrawing from the European Championships earlier this summer.

But she quickly dispelled that by producing some of her best performances to put her in position to finally lay to rest her demons in Olympic multi-eventing, injuries and errors having previously denied her a shot at a medal at three previous Games.

She looks in a strong position for a medal after the penultimate round of competition, the javelin, but the question remains which colour.

Her throw of 45.45metres in the first javelin group was a season's best but she had to sit and watch to find out what distance her gold-medal rival Nafi Thiam would throw.

Thiam unleashed a season's best of her own of 54.04 for a monstrous 939-point tally to move into the lead and 121 points ahead of Johnson-Thompson.

Were the pair to run their personal bests around two laps of the track - the Briton is six seconds quicker at the discipline - then Thiam would win gold by 30 points.

Johnson-Thompson started the morning with a poor opening jump in the long jump but finally landed a best of 6.40m, just a centimetre behind Thiam going into the javelin and leaving her in a marginal lead.

But there was a sense of frustration in that she has jumped more than half-a-metre further in the past although that was before undergoing Achilles surgery on her take-off leg.

Having been in the earlier javelin group, Johnson-Thompson at least has the benefit of an hour of additional rest to Thiam before they race for the gold inside the Stade de France at 7.25pm UK time.