London, Aug 14 (IANS): South African star Caster Semenya produced a strong finish to regain the mantle of world champion in the women's 800 metre event at the London Stadium here.

The reigning Olympic champion produced a time of one minute and 55.16 seconds -- the fastest in the world this year -- to win gold at the IAAF World Championships on Sunday night. 

This was the second World Championships gold in the 800m event for the 26-year-old. Her first World Championships title came at the 2009 edition in Berlin, a year after she won gold at the World Junior Championships.

Rio Olympics silver medallist Francine Niyonsaba of Burundi came in second with a time of 1:55.92 while American athlete Ajee Wilson finished third in 1:56.65.

Semenya has won every 800m race since finishing eighth at the ISTAF Meeting in Berlin in September 2015.

"I'm lucky to have a great support team who work with me. Full credit to them. Another world title is a fantastic honour for me and I love to do it here in London," she was quoted as saying by the official website of the International Association of Athletic Federations (IAAF).

"The crowd are so welcoming to me and it makes it feel even more special."

Niyonsaba and Wilson set the early pace with the former covering the first 200 metres in 27.08 seconds to be at the front of the leading pack.

The leading pack slowed down a bit thereafter with 57.98 seconds showing on the stadium clock at the 400m mark.

At the start of the final lap, Niyonsaba, Wilson and Kenya's Olympic bronze medallist Margaret Wambui made up the top three, with Britain's Lynsey Sharp just behind them. Semenya was trailing them at fifth.

It was with 250 metres remaining that the next significant move was made with Wilson kicking hard, but Niyonsaba wasn't happy to relinquish the lead and responded accordingly.

By now, the two were a few metres clear of the rest of the field and Semenya sensed enough danger to close down the gap.

Into the final straight, the three leaders were running side by side, Wambui having faded from contention. With 60 metres to go, Semenya moved clear and was able to maintain her pace till the finish.