Reigning world champion Jorge Lorenzo will miss Saturday’s Dutch MotoGP after fracturing his left collarbone in a 200 km/h crash during a wet practice session at Assen on Thursday.

The in-form Yamaha rider, on a hat-trick after wins in Spain and Italy, had posted the fastest time in first practice.

But in the second session, with standing water making life difficult on the circuit, he lost control at Turn 13, the rapid Hoge Heide right-hander.

He was flung over his handlebars, landing heavily on his left shoulder. An ambulance took him to the circuit’s medical centre, where his injury was confirmed.

He is due to be kept under observation at Assen hospital before being flown to Barcelona for surgery late Saturday or early Sunday, race organisers reported.

Xavier Mir, the doctor who first examined Lorenzo, told motogp.com: “Jorge has suffered an accident at over 200 kilometres an hour and the obvious injury at this point is a broken left clavicle.

“However, as this was a significant accident, we have to take into account that there could also be head, thoracic or abdominal injuries.

“For now, we have taken him to hospital in Assen where CT scans will be carried out in those three areas to rule out any further injuries.

“It would also be a prudent move to observe him over 12 hours to make sure he can be treated by the appropriate parties when he arrives in Barcelona.”

Lorenzo will be furious at his misfortune, having arrived in Assen seeking his third consecutive win after cutting Dani Pedrosa’s world championship lead to just seven points.

Marc Marquez posted the fastest time in the wet, lapping the track in 1 minute 47.617 seconds on his Honda.

Valentino Rossi was second for Yamaha and Pedrosa was third fastest.

Lorenzo’s latest accident follows first lap crashes in the Dutch MotoGP itself in 2011 and last year, when he failed to make it past the first corner.