A simmering battle in Formula One erupted in spectacular fashion on Sunday as championship leader Max Verstappen and defending champion Lewis Hamilton crashed out of the Italian Grand Prix, which was won by McLaren’s Daniel Ricciardo.

As both Hamilton and Verstappen fought for position midway through the race, their cars came together in a move that almost seriously injured Hamilton. Mercedes team principal Toto Wolff went as far as describing it as “a tactical foul” by Verstappen.

“The stewards will decide who is to blame,” Wolff said. “In football you would call it a tactical foul. He knew that if Lewis stays ahead, then that is the race win.”

The stewards did decide, judging that Verstappen “was predominantly to blame for the collision.” They gave the Red Bull driver a three-place grid drop for the start of the next race, the Russian GP on Sept. 26.

“I’m proud of the stewards,” Hamilton said after learning of their decision. “I need some time to really reflect on it but I think it definitely sets a precedent and I think it’s important for us moving forwards, for the safety of the drivers that there are strict rules set in place.”

Hamilton, who had been outspoken against the protective halo at the front of F1 car cockpits before its introduction in 2018, thinks it might have saved his life on Sunday.

“I don’t think I’ve ever been hit on the head by a car before. It’s quite a shock for me,” added Hamilton, who still sounded distressed several hours after the incident. “And I’ve been racing a long, long time. So I’m so, so grateful that I’m still here. I feel incredibly blessed. I feel like someone was watching over me today.”

Verstappen maintained his championship lead, which he had slightly extended to five points by coming second in the sprint on Saturday.

It was the second major incident between the two in as many months. They clashed on the first lap of the British GP in what Red Bull called a “desperate” move by Mercedes driver Hamilton that saw him given a 10-second penalty and Verstappen hospitalized.