ZANDVOORT – Championship leader Lewis Hamilton topped the first practice session for the Dutch Grand Prix on Friday which was cut short by nearly 40 minutes because of a problem with Sebastian Vettel's Aston Martin.
Hamilton clocked a quickest lap off 1:11.500 in his Mercedes, just 0.097sec ahead of title rival Max Verstappen of Red Bull at his home race.
They were followed by the Ferraris of Carlos Sainz and Charles Leclerq.
Valtteri Bottas, who is expected to be replaced by George Russell in the second Mercedes next year, was fifth quickest.
It is the first time since 1985 that Zandvoort has held a GP and the opening minutes of the session offered the drivers their first sight of a challenging track.
The hour-long session, though, was severely truncated when Vettel's car came to a stop at the exit of the pit lane, leaving a trail of oil behind it.
Vettel took a fire extinguisher from a marshall to put out a small fire but the car could not be touched as it was still electrically alive.
There was a lengthy delay before the car was covered in rubber sheets and then removed by the Aston Martin team.
With only six minutes left in the session, there was little time for the drivers to get a proper grip on the layout and the resultant traffic limited the opportunities to stretch the cars fully.
Yuki Tsunoda missed out almost entirely, spinning his Alpha Tauri on his first lap and not returning to the track.