O’Sullivan, a three-time Grade One-winning rider, was aboard Wee Charlie for Gerard O’Leary and was one of three fallers at the last in the two-mile handicap chase at the Tipperary track.

Two other runners were badly hampered as a result of the incident (unseating their riders) with the remainder of the meeting abandoned after the second race as the air ambulance arrived to take O’Sullivan to hospital.

Racing at Thurles was abandoned following the incident.

After a lengthy delay, an initial post on X from the Irish Horseracing Regulatory Board said: “The air ambulance has arrived at @thurlesraces and Michael O’Sullivan is being treated by the medical team on track.

“Due to the ongoing medical situation the remainder of the meeting has been abandoned.”

An update on X from Dr Jennifer Pugh, chief medical officer of the Irish Horseracing Regulatory Board (IHRB), said: “Michael is in the intensive care unit at Cork University Hospital being treated for his injuries sustained at Thurles yesterday and is receiving the best medical care.

“Michael’s family wish to express their gratitude for all the well wishes.”

O’Sullivan rose to stardom at the 2023 Cheltenham Festival when steering the Barry Connell-trained Marine Nationale to success in the Supreme Novices’ Hurdle at the Cotswolds.