Kimi Antonelli admits he "took it easy" as he returned to the wheel of a Mercedes in Mexico on Friday.
The 18-year-old, who is Ferrari-bound Lewis Hamilton's 2025 successor, rushed onto the throttle in his official practice debut at Monza recently - and crashed.
That was in George Russell's 2024, but this time in Mexico, Antonelli was driving Hamilton's F1 single seater.
When asked if he was worried the young Italian would also crash his car, seven time world champion Hamilton said on Thursday: "I don't personally feel that.
"Kimi is young, and he's learned from that first outing. We did our briefing together here, because he's working with Bono next year, and I said to him 'You don't have to set the world alight on the first lap'.
"Just build into it - enjoy. I told him the track is really dirty early on."
It is believed Antonelli's pace was ultimately affected by debris damage to the floor, but ultimately he did 19 laps - and was over a second off Russell's leading pace in the sister Mercedes.
"I didn't want to take any risks," he said. "I took it easy.
"We had a program to do with the team and I didn't want to make mistakes like in Monza," Antonelli told Sky Italia. "I felt I had margin, but there was no need to push.
"I'm happy. I gained experience. That's what I wanted to do."
