The first ever Tuscan Formula One Grand Prix at the Ferrari-owned Mugello circuit in Italy was stopped twice on Sunday after a spate of crashes and three safety car deployments.
The red flag first came out when Alfa Romeo's Antonio Giovinazzi, McLaren's Carlos Sainz, Haas's Kevin Magnussen and Williams' Nicholas Latifi collided at the end of a safety car period.
Valtteri Bottas had been leading for Mercedes, with team mate Lewis Hamilton second, and controlling the pace.
As the Finn prepared to accelerate away, the back-markers reacted as if the leaders had already re-started. Sainz hit the back of Giovinazzi's car as the Alfa swerved.
"I think people were going before you'd gone," Mercedes told Bottas.
Sainz reported that he and the others were okay. "The crash was really scary," he said.
"It felt like at the back of the grid where I was that everyone in front of me thought the race was going and we were all flat out until someone realised the race was not on," added the Spaniard.
"It's definitely not a nice feeling to do 280km/h and suddenly find three cars in the middle of the straight."
The safety car was immediately deployed again and the race then halted before a standing re-start.
The red flags came out again with 13 laps remaining, and Hamilton leading, when Canadian Lance Stroll suffered a puncture and crashed his Racing Point.
Frenchman Pierre Gasly, shock winner of last Sunday's Italian Grand Prix at Monza for AlphaTauri, brought out the first safety car after a crash that also took out Red Bull's Max Verstappen.
It was the second race in a row to be red-flagged.
Only 12 cars remained in the race.
