Montmelo:Mercedes driver Valtteri Bottas clocked the fastest time during the first practice session for the Spanish Grand Prix on Friday.
Red Bull driver Max Verstappen was next, followed by Formula One leader Lewis Hamilton in his Mercedes.
Only eight points separate Hamilton from Verstappen at the top of the standings after they finished 1-2 in the first three races.
Read:If India is not safe, better not to play T20 WC over there: Pat Cummins
McLaren drivers Lando Norris, the surprise of the season in a distant third place, had the fourth fastest time. Ferrari pair Charles Leclerc and Carlos Sainz were next.
The session under sunny skies near Barcelona only saw one red flag when Alfa Romeo reserve driver Robert Kubica spun out on a curve and got stuck in the gravel.
Nikita Mazepin also lost control of his Haas on one of his first laps, but he was able to get going again.
Read:Big blow to Saina, Srikanth's Olympic hopes as Malaysia Open suspended due to COVID-19 surge
Hamilton won the season-opener in Bahrain and last week's race in Portugal. Verstappen won the season's second race in Italy.
On Saturday, Hamilton will be aiming for his 100th career pole. On Sunday, he will be looking to equal Michael Schumacher's six wins in Montmel.
