A successful day on the track came to a sad end for leading Sydney trainer Chris Waller when stable favourite Rangirangdoo had to be put down after breaking down in the Doomben 10,000.

Rangirangdoo has been put down after breaking down in the Doomben 10,000. Photo by: Steve Hart.

The eight-year-old broke down past the 600m mark in the day’s feature race and vets were left with no other option.

Waller was always vocal in his admiration of the horse who succeeded in the top grade in the 2010 Doncaster Mile and the 2011 George Ryder Stakes.

From 34 starts the son of Pentire won 10 times and recorded 12 minor placings for more than $2.25 million in prizemoney.

The incident took the joy out of the day for Waller who won the BRC Sires’ Produce Stakes with Zoustar and the Grand Prix Stakes with Hawkspur.