Championship leader Lewis Hamilton won a wet Japanese Grand Prix from Mercedes team-mate Nico Rosberg on Sunday in a chaotic finish, but his victory was overshadowed by a serious crash involving Frenchman Jules Bianchi.
Bianchi was rushed to hospital unconscious after a shunt which brought the rain-hit race to premature halt to undergo emergency surgery for a serious head injury.
"Jules is seriously injured," Bianchi's father Philippe told France 3 television. "He is undergoing surgery for a head injury and we will need to wait 24 hours to know any more on his condition."
Formula One's governing FIA said in a statement that Bianchi had "suffered a severe head injury" and would be monitored from the intensive care unit following his operation.