Katarina Johnson-Thompson saw her chances of Olympic heptathlon gold begin to slip away after the javelin competition at Stade de France.
The Liverpudlian began day two at the top of the table, and retained her place after landing 6.40 metres in the long jump to retain a narrow 45-point advantage over the rest of the field.
The four-time Olympian threw a season’s-best 45.49 metres in the javelin, but double-defending champion Nafissatou Thiam landed a mammoth 54.04 for a season’s best of her own.
Johnson-Thompson’s two attempts were the second and third best javelin throws of her life, but Belgium’s Thiam now holds a 121-point lead with 5924 points heading into the final event, Friday evening’s 800 metres.
Johnson-Thompson is stronger than Thiam in the 800 metres, but her personal best 2:05.63, set last August, is closer to six seconds over Thiam’s 2:11.79, set this June.
The Netherlands’ Anouk Vetter, the Tokyo 2020 silver medallist, was challenging for another podium but dropped out of the competition ahead of her javelin throw with an injury.
Switzerland’s Annik Kalin sits third, 109 points behind Johnson-Thompson, whose GB team-mate Jade O’Dowda is 11th after six events.
Great Britain will go for gold in the men’s 4×400 metres relay final on Saturday night.
The quartet of Sam Reardon, Matthew Hudson-Smith, Toby Harries and Charlie Dobson were the second-fastest from the two heats in a season’s-best 2:58.88.
Quickest of the bunch were Botswana, thanks in part to a blistering 44.33 first leg from Letsile Tebogo, fresh from his 200 metres gold on Thursday night and a late call-up.
Botswana held an unassailable lead from the start, but Dobson was one of three men who had clawed back considerable distance around the final bend.
The Briton was in a tight battle with Japan’s Kentaro Sato down the final stretch before Christopher Bailey surged to snatch second for the United States.
Hudson-Smith, who claimed individual 400 metres silver for his first Olympic medal on Tuesday, said: “It’s been a hell of a two days, but I’ll find another gear for the final.
“Let’s get that medal, be a double Olympic medallist, and we can win it. We’ve got the team, we’ve got the mentality, we’ve got the coaches in Martyn Rooney and Darren Campbell, so let’s make history.
“We can do anything, we can get the British record, the European record. If we did good we could get the world record, anything is possible. We’ve got the team, we just need to execute and bring it home
“I think honestly for me, the individual medal was more so for my coach and my family, the relay is just for the boys and for myself.”
Max Burgin became the first British man to make an Olympic 800 metres final since Andrew Osagie at London 2012 in a personal best 1:43.50, third-fastest from the semis.
He said: “We watched (Keely Hodgkinson) with the team. It was an inspiring performance, and she just dominated that race.
“Not sure the men’s eights are going to go quite the same way. I think there’s a lot of top contenders, so I’d be surprised if it’s run in a similar way but it’s just great to watch a fellow GB athlete do that and now I’m in a position to contest the final as well.
“I think if there’s no pressure on, no expectation, I think you are a big advantage mentality wise. It’s a different level of stress entirely being the one going into championships that you’re expected to do the business.”
Ben Pattison and Elliot Giles, the latter a late call-up for the injured Jake Wightman, bowed out after their semi-finals.
Yemi Mary John, Hannah Kelly, Jodie Williams and Lina Nielsen qualified Team GB for Saturday’s women’s 4×400 metres relay final in a season’s best 3:24.72.
They booked the second of three automatic places from a heat absolutely dominated by a season’s best from the American team, who finished more than three seconds ahead of the British quartet.
Ireland are also through after 3:25.05 from Sophie Becker, Phil Healy, Kelly McGrory and Sharlene Mawdsley landed them third in heat two and seventh overall.
There was heartbreak in the third women’s 100 metres hurdles semi-final for Cindy Sember, who fell at the third-from-final hurdle.
