The leading jump jockey Kieran Kelly is described as critically ill after his fall at the Kilbeggan races on Friday night.
Kelly, stable jockey to trainer Dessie Hughes and a Cheltenham winner last March, is on a life support machine in intensive care at Dublin's Beaumont Hospital.
The Turf Club medical officer Dr Walter Halley said yesterday: "Kieran is critically ill. He is in Beaumont and is on a life support machine.
"I am not prepared to comment further other than to say that the people on the scene at Kilbeggan couldn't have done anything any better.
"The medical officers on duty, Ray Campbell and Gerry O'Flynn, as well as the officer in charge of the Order of Malta, Breda Colgan, were superb."
Kelly, 25, fell from Balmy Native at the fifth last fence in the handicap chase, received a kick to the head and was rolled on. He was taken initially to Tullamore hospital and later that evening to Beaumont.
From Carbury in Co Kildare, Kelly rode Hardy Eustace, trained by Hughes, to success in the SunAlliance Hurdle at Cheltenham in March.
That is the biggest success of his career but his best season in terms of winners remains the 32 he rode in 2000/'01.
Other good horses that Kelly has ridden include the double Grade One winner Colonel Braxton.