Lewis Hamilton set the quickest time of a heavily disrupted first practice at Zandvoort.
Red Bull’s Max Verstappen was second, 0.097 seconds behind his championship rival.
The session experienced a 33-minute delay due to the engine failure as the marshalls tried to clear away the Aston Martin, but were cautious due to concerns about the voltage of the car.
Thousands of Dutch fans poured into the circuit to witness Formula 1’s first visit to The Netherlands for 36 years but weren’t able to see much action due to the lengthy stoppage.
Before the red flag, most drivers opted for the hard tyres, but with limited time remaining after the delay, all went out on softs.
Sebastian Vettel was forced to become a fire marshal to deal with his Aston Martin that suffered a suspected power unit failure in first practice for the Dutch Grand Prix.
On F1’s return to Zandvoort after a 36-year delay, only 24 minutes of action were possible in the opening hour-long session at the circuit beside the seaside.
With just under 44 minutes remaining, Vettel brought out the red flags as his Aston Martin suffered a suspected power unit failure.
Vettel had earlier been informed of an MGU-K problem following his exploratory laps of the circuit, but after returning to the track, the AMR21 was soon forced to pull over.
With smoke starting to billow from the car, there was then the remarkable sight of Vettel claiming a fire extinguisher from a trackside marshal.
After initial teething problems in trying to operate the device, and seemingly heated discussions with the marshal concerned, Vettel finally managed to squirt foam over and inside the car.
However, there then appeared to be a further discussion as to whether he was using the correct extinguisher, as second and third systems were handed to the four-time champion.
Upon the arrival of a recovery truck a few minutes later, Vettel was still attempting to apply foam inside the car.
It then became a question of the safety of the car as no marshal was willing to touch it in order to strap it up so it could be loaded onto the truck and transported back to the garage.
It was not until a specially suited team member with a device to measure any likely electrical discharge had given the all-clear could the car finally be cleared, with the track only going green again with six minutes remaining.
As a circuit new to the calendar, with all bar home hero Verstappen not having driven the current revised configuration with its banking at turn three and the final corner, time on track was crucial to understanding the 2.6-mile, 14-turn layout.
The lost time was not what anyone would have wanted, but it was a circumstance beyond anyone’s control given the situation in front of packed grandstands, teeming with orange-clad Verstappen fans.
Once the green flag was shown, it was Mercedes’ Lewis Hamilton who topped the timesheet by just 0.097s to Red Bull’s Verstappen, setting a time of one minute 11.500secs.
The duo still managed 17 laps overall, two fewer than Ferrari’s Carlos Sainz who was third quickest ahead of team-mate Charles Leclerc, with the duo 0.101s and 0.123s behind Hamilton.
The Briton’s team-mate, Valtteri Bottas, was a further tenth of a second adrift in fifth.
There was then a gap of more than four-tenths of a second to Fernando Alonso in his Alpine, with the Spanish driver ahead of team-mate Esteban Ocon.
The top 10 was completed by Alfa Romeo’s Antonio Giovinazzi, Lance Stroll in the second Aston Martin and AlphaTauri’s Pierre Gasly, the latter a second back.
Lando Norris, who was forced off track and onto the grass in the dying moments by Ocon, was 11th, 1.179s down.
Vettel only managed six laps overall and was 19th on the timesheet, ahead of Yuki Tsunoda in his AlphaTauri, who failed to set a time following an early spin and failing to return.
2021 F1 DUTCH GRAND PRIX – FREE PRACTICE RESULTS (1)
| POS | DRIVER | NAT. | TEAM | TIME |
| 1 | Lewis Hamilton | GBR | Mercedes AMG Petronas Formula One Team | 1m11.500s |
| 2 | Max Verstappen | NED | Red Bull Racing | 1m11.597s |
| 3 | Carlos Sainz | ESP | Scuderia Ferrari Mission Winnow | 1m11.601s |
| 4 | Charles Leclerc | MON | Scuderia Ferrari Mission Winnow | 1m11.623s |
| 5 | Valtteri Bottas | FIN | Mercedes AMG Petronas Formula One Team | 1m11.738s |
| 6 | Fernando Alonso | CHI | Alpine F1 Team | 1m12.158s |
| 7 | Esteban Ocon | FRA | Alpine F1 Team | 1m12.231s |
| 8 | Antonio Giovinazzi | GBR | Alfa Romeo Racing Orlen | 1m12.359s |
| 9 | Lance Stroll | CAN | Aston Martin Cognizant Formula One Team | 1m12.431s |
| 10 | Pierre Gasly | FRA | Scuderia AlphaTauri Honda | 1m12.515s |
| 11 | Lando Norris | GBR | McLaren F1 Team | 1m12.679s |
| 12 | Nicholas Latifi | CAN | Williams Racing | 1m12.907s |
| 13 | Kimi Raikkonen | FIN | Alfa Romeo Racing Orlen | 1m13.053s |
| 14 | Daniel Ricciardo | AUS | McLaren F1 Team | 1m13.081s |
| 15 | George Russell | ISR | Williams Racing | 1m13.181s |
| 16 | Sergio Perez | MEX | Red Bull Racing | 1m13.328s |
| 17 | Nikita Mazepin | RUS | Uralkali Haas F1 Team | 1m13.516s |
| 18 | Mick Schumacher | GER | Uralkali Haas F1 Team | 1m13.847s |
| 19 | Sebastian Vettel | GER | Aston Martin Cognizant Formula One Team | 1m15.984s |
| 20 | Yuki Tsunoda | JPN | Scuderia AlphaTauri Honda | No Time Set |
