Valtteri Bottas continued his fine form by topping the third and final practice session for the Portuguese Grand Prix ahead of qualifying later Saturday.
After leading Friday's two practice sessions, the Mercedes driver was .03 seconds quicker than teammate Lewis Hamilton and .16 ahead of Red Bull's Max Verstappen.
Hamilton is aiming for a record-extending 97th career pole position. The runaway championship leader damaged the front wing after sliding off into gravel on a track hosting its first F1 race that has caused numerous drivers problems because of its lack of grip.
Ferrari driver Charles Leclerc again spun his car, as he had done on Friday.
Near the end of the session, a confused Leclerc asked his team over radio what was happening with his own, since he could hear Hamilton's radio messages. Leclerc was sixth fastest.
Hamilton's victory two weeks ago at the Eifel GP in Germany tied him Michael Schumacher’s F1 record of 91 wins in a season where he is odds-on to equal the German great's record seven F1 titles.
There were mask-wearing fans scattered around the undulating 4.6-kilometer (3-mile) circuit in Portimao, which has frequent elevation changes. It is the second new track on the coronavirus-hit calendar after the Tuscan GP in Mugello last month.
With one minute left, the session was stopped because of a loose drain cover on Turn 14.
Portugal last hosted a race in 1996, when three F1 champions made the podium after Jacques Villeneuve won ahead of Damon Hill and Schumacher in Estoril.