The Hungarian Grand Prix on Sunday was stopped on the opening lap after a crash on Turn 1 took out five cars including the Mercedes of Valtteri Bottas and the Red Bull of Sergio Perez.
Seven-time world champions Lewis Hamilton was ahead of the chaos in the rain but championship leader Max Verstappen was sent careening off the track and headed into the pits for repairs when the race was red-flagged.
Ferrari's Charles Leclerc, the Aston Martin of Lance Stroll and the McLaren of Lando Norris were also involved in the accident and knocked out of the race.
Two weeks ago, the British Grand Prix at Silverstone had an equally controversial start as Hamilton and Verstappen touched wheels on the opening lap.
Verstappen went spinning off and Hamilton, in spite of a 10-second penalty, went to win, closing the Dutchman's championship lead to just eight points.
It led to a fortnight of recrimination between Red Bull and Mercedes which is likely to resume after Bottas appeared to cause the first lap chaos in Hungary.
Bottas started slowly and when Norris came across him, the Finn braked late creating a domino effect of bumper cars.