Shaken Matt LeBlanc took time off filming Top Gear after nearly driving over a cameraman in a Porsche.
The Friends star had jumped in to take the test motor for a spin during a break in shooting – not realising one of the crew was lying down filming at ground-level.
And he was only stopped from zooming off when another cameraman began waving and shouting in the distance after spotting the drama unfolding.
A show insider told the Mirror: “In between filming, Matt got into a Porsche they’d been road-testing, turned on the ignition and was about to take it for a drive.
“But he was completely unaware one of the cameramen was lying down alongside it at ground level, filming low shots.
“The crew member was completely oblivious Matt was about to speed off, too – but a tracking cameraman, who was sat in the distance, could see what was about to happen and started waving and screaming at Matt to stop.
“Matt was a bit confused but got out of the car. When he realised he could have run the man over he was noticeably shaken up. He said he needed a bit of time out.
“He reappeared a few hours later, wanting to know that the cameraman was OK – which he was. He said, ‘Where’s that guy I nearly ran over?’
“It was one of those instances where, if the tracking man and Matt had reacted even a few seconds later, it could have been really serious. Both of them appreciated what a lucky escape it was.”
The incident happened last month as Matt, 48, was filming segments for the newly revamped series in South Africa.
A BBC spokeswoman declined to comment.
Top Gear is due to return to BBC2 in May.