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Video - Robles on course for hurdles gold
World record holder Dayron Robles reaffirmed his status as overwhelming favourite for 110m hurdles gold with a commanding victory in his semi-final.
The Cuban came under brief pressure from France's Ladji Doucoure before winning heat one in 13.12 seconds.
Doucoure eventually finished third, with David Payne coming through in second and Richard Phillips fourth.
David Oliver won heat two in 13.31sec as Artur Noga, Jackson Quinonez and Jackson Maurice Wignall also qualified.
Robles has been drawn in lane six and Oliver in seven for the final, which takes place at 1440 BST on Thursday.
The US hurdler remains the only man to have beaten Robles this season but the latter is expected to prevail.
The withdrawal of reigning champion Liu Xiang of China has increased the chance of Robles, 21, adding the Olympic title to his world record, set in the Czech Republic in June.