Nyairera faces gold favourites Semenya and Niyonsaba tonight

World Championships Kenya's Margaret Nyairera Wambui poses for the TV camera after winning a Women's 800m heat during the World Athletics Championships in London, Thursday, Aug. 10, 2017. (AP Photo/David J. Phillip)

Olympic 800m bronze medalist Margaret Nyairera faces a tough test tonight.

Nyairera will battle against favourites South Africa’s Olympic champion Caster Semenya, silver medalist Francine Niyonsaba of Burundi and America’s Ajee Wilson in the final.

In the semis on Friday night, there were 15 runners with season’s bests below two minutes, with nine of those times quicker than 1:59, and throw in the fact that championships racing is often tactical, predicting the first two automatic qualifiers wasn’t an easy task.

Semenya, Niyonsaba, Nyairera and Wilson all progressed in serene fashion, although it doesn’t take a mathematician to observe that four into three podium positions is a difficult equation to square.

The first race featured the 23-year-old Wilson, who set the USA national record 1:55.61 in Monaco last month.

The second semi-final featured Semenya, who took a bronze medal in the 1500m on Monday. In the heats, she had waited until the final 70m before surging through to win, but here she reacted to the gun like a sprinter, attempting to hit the front at the break.

It was Great Britain’s Olympic finalist Lynsey Sharp who actually led, edging Switzerland’s Selena Buchel, before Wilson’s training partner Charlene Lipsey hit the front, running 28.1 for the first 200m.