Lewis Hamilton trailed Mercedes team-mate Valtteri Bottas in the opening practice session for the Portuguese Grand Prix in his quest for a record 92nd win.
Portimao, here in the Algarve, is hosting its first Formula One race following this year's coronavirus-disturbed calendar.
But it was business as usual for the all-conquering Mercedes team, with Bottas leading the way from Hamilton.
It marked the seventh opening running in succession where the Finn has headed the time charts.
After equalling Michael Schumacher's victory record at the last round in Germany, Hamilton is now bidding to become the sport's standalone most successful driver this weekend.
On the evidence of the initial track action on Friday morning, Bottas will be his sole contender for the spoils as Mercedes' impressive pace carried over to the 12th of 17 rounds.
Hamilton finished 0.339 seconds adrift of Bottas, whom he leads by 69 points in the standings on his inevitable march towards a record-equalling seventh world title.
Red Bull's Max Verstappen was third in the order, 0.781 sec behind Bottas and Ferrari's Charles Leclerc fourth.
Both Verstappen and Leclerc spun with the drivers struggling to find grip on a track last visited by F1 during a pre-season test in 2009.
Leclerc was fortunate to tip-toe his way out of the gravel at the penultimate corner after he lost control of his Ferrari.
Alexander Albon took fifth for Red Bull, nearly one second down on Bottas, while McLaren driver Carlos Sainz was sixth.
British driver Lando Norris finished 12th in the other McLaren. Four-time world champion Sebastian Vettel, who is enduring the worst year of his career, could manage only 11th, the best part of a second slower than team-mate Leclerc.
The 90-minute session ended with trouble for Esteban Ocon as smoke poured out of the back of his Renault. The Frenchman was immediately told to pit by his concerned team.
