The Dane had just completed his first installation lap and was being wheeled back into the Renault garage when flames erupted at the top of the engine cover. He jumped clear and the team rapidly fought the flames, but with fuel continuing to leak, the car continued to catch fire, meaning it took around 10 minutes to bring the situation fully under control.
Renault technical director Nick Chester says early indications point to a build up of pressure within the fuel tank being to blame - but he remains confident that Magnussen, who was uninjured in the incident, will be able to get out in FP2.
"We had a fuel leak from a breather," Chester said. "It looks like the tank pressurised, but we will investigate. We were running the tank full and we were running some experimental parts really in preparation for Mexico, so different set-up to the other [Jolyon Palmer's] car.
"Everyone's okay, that's the main thing. Fortunately the car doesn't seem to be too badly damaged so we'll try and get it out for P2. There is obviously a fair bit of work to do, and a fair bit to clean, but we'll try to get him out for as much of the session as we can."