Dean Berta Vinales, Alejandro Carrion, Daniel Mogeda, Harry Khouri and Yeray Ruiz were involved in a major crash at Turn 2 at the start of Lap 11, prompting race officials to report the session.
The race was not restarted and the results were announced at the end of the previous lap, giving Jeffrey Buis a narrow victory over compatriot Kawasaki Inigo Iglesias.
The WSBK race was scheduled to start at 2 p.m. local time, approximately 50 minutes after the red flag of the WSSP300 race.
But the start was delayed due to “track safety conditions” before the championship announced at 13:48 the total cancellation of the race.
In a brief statement, the WSBK noted that “following an incident in # WorldSSP300 Race 1 involving # 25 Dean Berta Vinales, the remaining on-track activity on Saturday was canceled”.
In addition to the WSBK, the weekend’s opening World Supersport race was also scheduled for Saturday afternoon.
Vinales, 15, is the cousin of nine-time MotoGP race winner Maverick and competed in his rookie season in WSSP300 for family team Vinales Racing Team aboard a Yamaha R3.
The championship has yet to provide an update on his condition.
Yamaha’s Toprak Razgatlioglu was due to start Race 1 from pole position after beating the Kawasaki of Alex Lowes and Jonathan Rea in qualifying.