|World Athletics Championships on the BBC|
|Venue: London Stadium Dates: 4-13 August|
|Coverage: Live across BBC One and Two, BBC Radio 5 live, BBC Radio 5 live sports extra, the BBC Sport website and app. Click for times|
Katarina Johnson-Thompson produced a fine display to win her 200m heat and move fourth after four events of the heptathlon at the World Championships.
The Briton, 24, reached only 1.86m in the high jump and was 13th in the field after a 12.47m shot-put in event three.
A time of 22.86 seconds in the 200m, just outside her best of 22.79, put her on 3,838 points, with Cuba's Yorgelis Rodriguez third on 3,905.
Carolin Schafer (4,036) leads Olympic champion Nafissatou Thiam by 22 points.
Germany's Schafer ran a 23.58-second 200m to put her second in Johnson-Thompson's heat but was considerably quicker than Belgium's Thiam, who dropped from gold-medal position after her 24.57 run.
Schafer, 25, was fifth at the Rio Olympics, where Thiam, 22, landed her first major title. They look set for a fierce battle over Sunday's long-jump, javelin and 800m finale.
Johnson-Thompson at least has hope of a first medal at a major championships, though she historically loses ground in the javelin. Her best mark of 42.01m is more than six metres behind what third-placed Rodriguez threw when finishing seventh at Rio 2016.
Earlier on Saturday, Johnson-Thompson cleared 1.80m easily in the high jump but failed three times at 1.86m. The Liverpool Harrier knelt with her head in her hands on the landing mat as she failed at 12cm short of her personal best.
Analysis - 'If we go to 800m now'
BBC Radio 5 live commentator Mike Costello: "If we were to stop now and go to the last event, the 800m, KJT would have to beat Yorgelis Rodriguez by five seconds. Of course, positions will change between now and then but at the moment, Johnson-Thompson is right back in it."
Rodriguez has an 800m personal best of two minutes 12 seconds, set this year, while Johnson-Thompson clocked 2:07.64 in 2013.