Lashawn Merritt of the United States and Kirani James of Grenada have been the most dominant male 400 metre runners for the last two years. However, in a few days we could see the changing of the guard in Beijing.

South Africa's Wayde Van Niekerk is a live threat and could give that country its first major 400m title.

Entering the season, all eyes were on the Merritt-James rivalry.

James, who had won two global titles in a row, World Championships 2011 and Olympic Games 2012, and Merrit, the defending World champion, looked a cut above their counterparts.

Things have changed significantly this season with Van Niekerk looking likely to spoil that party.

Despite the credentials of the three, it is Botswana's, Isaac Makawla, who is going into the championships as the number one after a world-leading 43.72 seconds done in high altitude.

Merritt has not looked his usual self this season and has been beaten on a regular basis.

If he hopes to retain his title, he will have to improve big time on his season's best 44.36 seconds set in Edmonton, Canada, last month.

After winning his first major senior title four years ago, many experts thought James would have dominated for a long time.

He underlined that in 2012 when he won at the London Olympics from which injured Merritt was absent.

James started this season in fine style, dominating the event with ease before running into Van Niekerk at the Paris Diamond League.

The South African had shown in New York earlier that he was on a mission, destroying a strong field to win impressively.

Blessed with good 200m speed, the South African tracked James for the first 350m before running past him easily to win in an impressive personal and season's best 43.96 seconds.

James could have taken Van Niekerk a bit lightly, and will know now that he could be his biggest danger. He will want to set matters straight in Beijing.

TOP 3

1. Wade Van Niekerk (RSA) 2. Kirani James (Gren) 3.Lashawn Meritt (USA)

-R.G.