Katarina Johnson-Thompson claimed a stunning heptathlon gold medal at the World Championships.

Defending champion Nafi Thiam, of Belgium, was upset in Doha on Thursday.

Here, the PA news agency looks at the talking points surrounding Johnson-Thompson's victory.

How impressive was it to topple Thiam?

Previous world champion Thiam has been virtually untouchable for the last three years, winning world, European and Olympic titles. She had not lost since Gotzis in 2016. Johnson-Thompson pushed her close last summer, coming second by 57 points at the European Championships in Berlin. In Doha, Thiam was clearly struggling with a long-standing elbow problem but Johnson-Thompson produced the best performance of her career for a brilliant victory.

What does gold mean?

It continues her progression since she moved to Montpellier to train in early 2017. She won the World Indoor pentathlon title, the heptathlon at the Commonwealth Games and European silver last year. Previous mistakes at the World Championships in 2015 and 2017 cost her but Johnson-Thompson is now a proven performer on the big stage.

Is the Olympic title between Johnson-Thompson and Thiam?

It is difficult to see any others breaking the pair's stranglehold on the top two, unless the favourites slip up. Johnson-Thompson's European silver was a world silver in all but name last year given the strength of the field and she has now followed that up by beating Thiam for the first time. Ivona Dadic pulled out after the first event and there was no Carolin Schafer, who won European bronze last year, and it looks like a straight fight between Thiam and Johnson-Thompson in Tokyo.

Has Johnson-Thompson banished her demons on the world stage?

Emphatically so. She has learned from mistakes which have proved so costly in the past. In Beijing in 2015 – where she fouled all her long jump attempts – and 2017, where a poor high jump let her down, she was left floundering. At the Rio Olympics she was not 100 per cent fit but she is now putting consistent performances together when it matters.

What were the fine margins in Doha?

Personal bests in the 100m hurdles, shot put and javelin – with the throws her weakest events – helped give Johnson-Thompson a stunning victory. Thiam struggled in the long jump and javelin as the pendulum swung to Johnson-Thompson early in competition on Thursday. She has sounded the charge heading to Japan next year.