Spa-Francorchamps, Belgium - Sebastian Vettel topped the timesheets from Ferrari team-mate Charles Leclerc in first practice for the Formula One Belgian Grand Prix on Friday.
Vettel posted a best 1 minute 44.574 seconds around the iconic 7.004 kilometres of the Spa-Francorchamps circuit, 0.214 seconds ahead of Leclerc.
Max Verstappen was third but 0.933 seconds behind in his Red Bull.
Mercedes had a low-key session with standings leader Lewis Hamilton sixth after suffering a throttle pedal problem early in the session and Valtteri Bottas, the day after extending his contract for next season, was one better in fifth.
The reigning world champions were using the medium rather than soft tyres however and will expect to improve in second practice later Friday.
Alexander Albon impressed in his first outing for Red Bull after promotion from Toro Rosso with fourth.
Hamilton is chasing a sixth world title and leads the drivers' championship by 62 points from Bottas going into Sunday's race, the first after the mid-season break.
Vettel has now reached a year since his last win which came at Belgium 2018 and will look to build on his strong start in qualifying on Saturday.