Red Bull's Formula One championship leader Max Verstappen set the pace in first practice for the Azerbaijan Grand Prix on Friday, with the two Ferraris close behind.
The 23-year-old Dutch driver, leading the standings for the first time in his career after winning in Monaco last month, lapped the Baku street circuit with a best time of one minute 43.184 seconds.
Ferrari's Monaco Grand Prix pole-sitter Charles Leclerc was the second fastest, 0.043 slower, with Spanish team mate Carlos Sainz third in the sunny session.
Seven times world champion Lewis Hamilton, four points behind Verstappen after five races, was only seventh fastest with team mate Valtteri Bottas -- winner in Baku in 2019 -- 10th.
Both were slowed by traffic on quick laps, however, and the 'dirty' track proved slippery for drivers who also had to contend with breezy conditions.
The weekend has been dominated by a row over 'bendy' rear wings, with the governing FIA keeping a close eye on the situation before introducing new tests at the following French Grand Prix.
Verstappen's Mexican team mate Sergio Perez, a two times podium finisher in Baku with now-defunct Force India, was fourth on the timesheets.
Australian Daniel Ricciardo, a winner in Azerbaijan with Red Bull in 2017, was fifth for McLaren and AlphaTauri's Pierre Gasly sixth.
The race in Baku was not held last year due to the Covid-19 pandemic and will be held without spectators this weekend.