at the Union Buildings in Pretoria
London - American Aries Merritt raced a scorching 12.94sec to lead all the favourites, including defending Olympic champion Dayron Robles, into Wednesday's 110m hurdles final.
In the absence of China's 2004 Olympic champion Liu Xiang, who crashed out in the heats on Tuesday, Merritt won his heat from Barbadian Ryan Brathwaite.
Merritt's US teammate Jason Richardson, the shock world champion from last year in Daegu, won his heat in 13.13sec, and Robles of Cuba clocked 13.10sec in winning the third semi-final.
Also going through to the final will be Jamaican Hansle Parchment and Cuban Orlando Ortega, with South African Lehann Fourie and Briton Lawrence Clarke advancing as the two overall fastest finishers outside the two automatic spots from each semi-final. - AFP