Max Verstappen suffered a car failure early in Dutch Grand Prix first practice and managed only seven laps as Mercedes set the pace with a one-two.
Verstappen, the runaway championship leader after a series of Ferrari foul-ups, stopped on track with what Red Bull said was a transmission problem.
He was fastest at the time but slipped down to 19th out of 20 runners.
George Russell was fastest by 0.240 seconds from Mercedes team-mate Lewis Hamilton with Carlos Sainz third.
Mercedes set their times on the fastest soft tyre much later in the session than most others, so their times are not necessarily comparable.
Ferrari’s Sainz was 0.390secs off the pace, with McLaren’s Lando Norris less than 0.1secs further back in fourth.
The second McLaren of Daniel Ricciardo was fifth, ahead of Verstappen’s main title rival Charles Leclerc of Ferrari, Red Bull’s Sergio Perez and Alpine’s Fernando Alonso and Esteban Ocon.
No-one crashed as the teams returned to the seaside Zandvoort circuit, which last year was reintroduced to the calendar for the first time since 1985 as F1 and local organisers sought to capitalise on Verstappen’s huge popularity in his home country.
A few drivers ran wide through gravel traps – including Perez and the Haas drivers Mick Schumacher and Kevin Magnussen – but there were no serious incidents.
Drivers were asked to try using the DRS overtaking aid through the banked final corner with the intention of it being in place for the race to aid overtaking, which is traditionally tricky at Zandvoort. As expected, none reported any issues.
