Bolt on track for treble

London - Usain Bolt's dream of replicating his Beijing golden treble was kept alive on Friday as his team-mates coasted through to the final of the 4x100m relay with ease.

Nesta Carter, Michael Frater, double sprint silver medallist Yohan Blake and Kemar Bailey-Cole timed 37.39sec to win their heat from Canada.

It meant that Bolt, who notched up the unique feat of defending both his 100m and 200m crowns here, will have a chance for a third gold when he doubtless takes to the track in Saturday's final.

The US team of Jeffery Demps, Darvis Patton, Trell Kimmons and Justin Gatlin then went one-hundredth of a second faster than the Jamaicans in the second semi.

But there was heartbreak for Britain, with Daniel Talbot's last changeover to Adam Gemili occurring outside the exchange zone, resulting in the quartet being disqualified.

Making up the final will be Japan, Trinidad and Tobago, France, Australia and the Netherlands.