The 27-year-old Olympic champion, who presently shares the record of eight titles with retired compatriots Carl Lewis and Michael Johnson, looked in the sort of condition she needs to be in to win her fourth world title in the event.

However, Felix will have taken note of the form of Jamaica's 100m champion Shelly-Ann Fraser-Pryce, who looked to be in better shape than she was last year when finishing a well-beaten second in the Olympic final.

Felix did the necessary work on the bend in her semi-final, coming off it with Nigeria's Blessing Okagbare on her shoulder and well clear of the remainder of the field.

Both coasted to the line, Okagbare achieving the rare feat of reaching her third final of the week, the 24-year-old having finished second in the long jump and sixth in the 100m.

Felix was satisfied with her performance. "I felt really comfortable out there, my fitness seems to be really good," she said.

Fraser-Pryce also had the race in her pocket coming off the bend and, showing little sign of the pain she felt in her left buttock in the 100m final, finished metres clear of her rivals.

Ukraine's Mariya Ryemen got the crowd - at least the blocks occupied by young Ukrainians dressed in the national colours of yellow and blue - cheering as she passed Anthonique Strachan to take the second of the two automatic qualifying spots.

Fraser-Pryce threw down the gauntlet to her main rival in no uncertain terms. "Physically I feel excellent, I just need to focus myself mentally on what I have to do," said the diminutive 26-year-old. "However, I know I'm already the best, that I know for sure."

Ivory Coast's 100m silver medalist Murielle Ahoure showed she will be a medal contender again with a powerful performance in her semi-final, the 25-year-old streaking clear to time 22.46sec.

Ahoure, known as the 'female Drogba' in the Ivory Coast in reference to the country's footballing great Didier Drogba, said that she had overcome a sore throat in the morning - when she had still won her heat - and was feeling right up for taking on the two favourites. "Everything went right here. I was super-relaxed and hopefully I feel the same way in the final," she said. "There is no reason why not as the medal in the 100m has got my confidence on another level." (AFP)