Kevin Magnussen was fastest in the Young Driver Test in Abu Dhabi today.
The test gives Formula 1 teams a chance to put potential future drivers behind the wheel.
The Dane joined McLaren's Young Driver Programme in 2011.
Sauber's Robin Frijns, who was fourth quickest, told Sky Sports News: "Gosh this was hard work! Not in the beginning but then suddenly I felt it, especially from the brakes. I am really tired now and know I have to go and exercise more.
"There is obviously a lot to learn. On my fastest lap with the soft tyres I made a mistake, so there was more to come. The team did a great job during the day and I want to thank them for that."
The test continues tomorrow.
