Katelyn Mallyon's first Group One win has brought with it a careless riding suspension on Silent Sedition in the William Reid Stakes at Moonee Valley.

Mallyon and Caulfield trainer Andrew Noblet both recorded their maiden Group One wins when Silent Sedition scored narrowly on Friday night from the Darren Weir-trained Hellbent.

But Mallyon's actions early in the race earned her the suspension when she was found to have allowed Silent Sedition to shift in when insufficiently clear of Hellbent at the 900m.

Mallyon pleaded guilty and will be out until after April 1.

Silent Sedition is scheduled to run in the Queen Of The Turf Stakes at Randwick a week later.