Valtteri Bottas set the pace for Mercedes in the first Portuguese Grand Prix practice in 24 years on Friday, with six-time Formula One world champion team mate Lewis Hamilton second fastest.
The Finn has made a habit of going quickest in the first session of the race weekend, doing so eight times in a row even though the only practice two weeks ago at the Nürburgring was on the Saturday due to bad weather.
The Friday morning prowess has not translated into wins on Sunday, however, with Bottas 69 points adrift of Hamilton after 11 races.
Hamilton, who was 0.339 seconds slower than Bottas's best effort of 1:18.410 on medium tyres around the undulating Algarve International Circuit near the southern city of Portimao, has seven wins to Bottas's two.
The Briton will be chasing a record 92nd career win on Sunday, having matched Michael Schumacher's all-time milestone at the Nürburgring on October 11.
Red Bull's Max Verstappen was best of the rest on a cloudy morning, clocking a time 0.781 slower than Bottas but on hard tyres, with Ferrari's Charles Leclerc fourth as the field came to terms with a new track on the calendar.
Verstappen's Thai team mate Alexander Albon was fifth on the time sheets with McLaren's Carlos Sainz sixth.
Renault's Esteban Ocon suffered an apparent engine problem at the end of the session.
The last Portuguese Grand Prix was held at Estoril, near Lisbon, in 1996.
