In her first individual outing of the season, Yemi Mary John has produced the unexpected. In Tokyo, at the Seiko Golden Grand Prix, the 23-year-old British athlete became only the ninth woman in United Kingdom history to run under 50 seconds for the 400m thanks to a stunning 49.85 performance. It was a major breakthrough for the 2022 World U20 champion, who also recorded the fastest European time of the year and the fifth-best mark in the world this season. Above all, the race further confirmed that the current depth of British women’s 400m running is probably the strongest it has ever been.
A historic first outdoor individual appearance of the season
There had already been very encouraging signs in Gaborone at the World Relays two weeks ago. Within a remarkably deep British squad, Yemi Mary John once again demonstrated her value by delivering an outstanding anchor leg in the mixed relay, including a flying split of 49.15 seconds in the heats. But this time in Tokyo, the British athlete delivered a completely different kind of statement on an individual level.
For her first outdoor individual race of the year, Yemi Mary John completely shattered her personal best. By winning in 49.85, well clear of American Bailey Lear (50.42), she took 0.65 seconds off her previous best set last year in Bergen (50.50).
While her potential had never really been questioned, her progression against the clock had slowed slightly after winning the World U20 title in Cali in 2022 with 51.50. In 2023, she lowered her best to 51.04 before enduring a more inconsistent 2024 season, which ended with a best of 51.18. Last year, her breakthrough below the 50.50 barrier at the European U23 Championships in Bergen already felt like a turning point. Even so, very few expected such a dramatic leap as early as May 2026.
The performance now lifts her to seventh on the British all-time rankings, ahead of Laviai Nielsen and Jodie Williams among others. Yemi Mary John also becomes the youngest British athlete to break 50 seconds in more than two decades in an event where the United Kingdom possesses a rich tradition, from Kathy Cook and Christine Ohuruogu through to current national record holder Amber Anning.
The wider context makes the run even more impressive. Producing a 49.85 in her first outdoor individual race of the season inevitably suggests there could still be more to come later in the summer, especially with the European Championships in Birmingham on the horizon. Although athletics remains unpredictable and seasons rarely follow a perfectly linear trajectory, this mark could yet be lowered again over the coming months.
Now ranked fifth in the world for 2026 and number one in Europe this season, Yemi Mary John has firmly established herself among the world elite. More importantly, she further strengthens the growing feeling that British women’s 400m running is currently experiencing a genuine golden era.
Alongside Amber Anning (49.29), the return to form of Laviai Nielsen, the emergence of Charlotte Henrich and the development of athletes such as Emily Newnham and Rebecca Grieve, the United Kingdom now possesses exceptional depth, but above all an incredibly young group of athletes. The only remaining question is just how far this progression can take them.
British women’s all-time top 10 over 400m
- Amber Anning — 49.29 — Paris (France) — 9 august 2024
- Christine Ohuruogu — 49.41 — Moscow (Russia) — 12 august 2013
- Kathy Cook — 49.43 — Los Angeles (USA) — 6 august 1984
- Katharine Merry — 49.59 — Athens (Greece) — 11 june 2001
- Nicola Sanders — 49.65 — Osaka (Japan) — 29 august 2007
- Donna Fraser — 49.79 — Sydney (Australia) — 25 september 2000
- Yemi Mary John — 49.85 — Tokyo (Japan) — 17 may 2026
- Laviai Nielsen — 49.87 — London (United Kingdom) — 20 july 2024
- Jodie Williams — 49.97 — Tokyo (Japan) — 4 august 2021
- Phylis Smith — 50.40 — Barcelona (Spain) — 3 august 1992
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