Mo Farah won the final track race of his career by the skin of his teeth on Thursday, clinching a dramatic 5,000 metres win after three chasing Ethiopians collided with each other as they approached the finish line.

The quadruple Olympic champion led down the final straight but world champion Muktar Edris came powering through and appeared set to sneak victory on the line.

However Edris fell to the ground after being clipped from behind by his fellow Ethiopian Paul Chelimo, in turn tripping Yomif Kejelcha on the outside.

Chelimo stumbled over the line in second and Edris's momentum took him over in third.

Briton Farah, beaten by Edris in the World Championship 5,000 metres final two weeks ago, will run marathons from next year.