Former Melbourne Cup winner Efficient has been retired, after the stayer picked up an injury on Thursday morning.
The Lloyd Williams-owned nine-year-old, who sensationally took out the 2007 Melbourne Cup in devastating style, hurt his leg at trackwork and will not race again.
The news was confirmed late on Thursday morning when Williams' son took to Twitter.
"Efficient has been retired after suffering a leg injury this morning," Nick Williams tweeted.
The Robert Hickmott-trained gelding won seven times from 29 starts, with his most high profile victory coming on the first Tuesday in November five years ago when ridden by Michael Rodd.
Efficient also took out the Group 1 Turnbull Stakes in 2009 and was being set for either the Melbourne Cup or Cox Plate, before picking up the injury.