In-form jockey Beau Mertens has been transported to hospital following a fall in the opening race at Stony Creek.

Mertens was riding the $1.65 favourite Nobiallo in the San Remo Hotel Maiden Plate (1100m) on Tuesday when the first starter fell heavily near the 200m mark.

Just Bolts, who was following, fell over the top of Nobiallo.

The Victorian Jockeys' Association issued a statement that Mertens was conscious, moving all limbs and being transported to hospital for observation while Thomas Stockdale, who rode Just Bolts, walked backed to the jockeys' room unaided but stood down from his remaining rides. reported Nobiallo was humanely euthanised as a result of injuries received in the incident.

A former leading apprentice who once challenged Craig Williams for Melbourne Jockeys' Premiership honours, Mertens rode a double at Caulfield last Saturday and is currently sitting fourth on the Victorian Jockeys' Premiership this season.