BEIJING (AFP) - Usain Bolt celebrated another memorable world championships by winning a third gold medal on Saturday as the anchor of the Jamaican 4x100m team.

He ran the final leg of the relay at a packed Bird's Nest stadium, hurtling through the line in 37.36 seconds after team-mates Nesta Carter, Asafa Powell and Nickel Ashmeade had got the baton around.

The US quartet of Trayvon Bromell, Justin Gatlin, Tyson Gay and Mike Rodgers were initially awarded silver but were later disqualified.

China delighted the home crowd when they were upgraded to a shock silver in 38.01sec while Canada were awarded bronze (38.13).