Japan's Shoya Tomizawa has died following a crash during the Moto2 race at Sunday's San Marino Grand Prix.
The 19-year-old was airlifted to hospital following a crash involving Italy's Alex de Angelis and Britain's rider Scott Redding where he was propelled off the Misano circuit.
He was taken to the Riccione Hospital but despite emergency medical attention was pronounced dead shortly after arriving.
Tomizawa rose to prominence after winning the first ever Moto2 race in Qatar at the start of the season.
"On Sunday 5th September during the Moto2 race, rider Shoya Tomizawa aged 19 suffered a serious crash and subsequent cranial, thoracic and abdominal trauma," read a statement on MotoGP's official website.
"Tomizawa was taken to the Hospital of Riccione for immediate treatment but succumbed to his injuries at 14.20.
"All the MotoGP family wants to express its deepest condolences to his family and friends."
Spain's Dani Pedrosa went on to win the following MotoGP race but admitted afterwards that it was a difficult afternoon for all the riders concerned.
"It feels so strange, there is a big hole inside me," he told BBC Sport.
"I was so happy and then I was told and this big hole opened up inside me."