A chaotic start to the Mexican Grand Prix saw a number of drivers forced to retire for various reasons, including a former world champion.
A pair of mid-pack drivers, Alex Albon and Yuki Tsunoda, made contact partway down the main straight on the opening lap, bringing out a belated safety car to clear up the debris and stranded cars.
The third retiree was Fernando Alonso, the Spaniard's 400th Formula 1 race coming to a disappointing end just 16 laps into the race when he pulled into the Aston Martin garage to retire his car.
It wasn't immediately clear what the two-time world champion's issue was, but the team later revealed that he was struggling with a suspected break cooling issue.
Alonso had talked throughout the trip to Mexico about his milestone race, becoming the only driver to reach 400 races entered and saying, perhaps optimistically: "I hope to enjoy the weekend, every second of it."
Meanwhile on track, the action was hectic. Lando Norris overtook Max Verstappen once racing got back underway after the safety car prompted by Tsunoda and Albon's crash, setting in motion a chain reaction of chaos.
Verstappen has been fighting his British title challenger to the very limit of the rules this season, and the FIA stewards took the view that he crossed the line with his actions following the Norris pass, giving him a pair of 10-second penalties for crossing the line when fighting the McLaren driver.
Meanwhile, the Ferraris of Carlos Sainz and Charles Leclerc drove away up the road ahead of the title battle for the second race in a row.