Barcelona - Valtteri Bottas set the early pace for Mercedes in first practice for the Spanish Formula One Grand Prix on Friday with Ferrari's Sebastian Vettel and Charles Leclerc close behind.
Five-times world champion Lewis Hamilton, Bottas's team-mate, lapped fourth fastest.
Despite his best lap of one minute 17.951 seconds on the soft tyres, on a sunny morning at the Circuit de Catalunya, Bottas missed the last half hour due to an oil leak that shut down the car and had to be investigated.
Vettel lapped in 1:18.066 with Leclerc's best time a 1:18.172.
Champions Mercedes have won the first four races of the season with one-two finishes, with Bottas leading Hamilton by a single point thanks to his fastest lap in the Australian season-opener.