Belgian GP: Sebastian Vettel heads Max Verstappen and Lewis Hamilton

Follow live audio and text commentary of the second practice session on the BBC Sport website from 13:30 BST

Sebastian Vettel set the fastest time in first practice at the Belgian Grand Prix as the Formula 1 season restarted after its summer break.

The Ferrari driver headed Red Bull's Max Verstappen and championship leader Lewis Hamilton, whose Mercedes was 0.318 seconds off Vettel's pace.

Hamilton leads Vettel by 24 points with nine races left.

Hamilton's team-mate Valtteri Bottas, who was fifth, will start from the back because of engine penalties.

Both Mercedes drivers have new, upgraded engines for this weekend and that has taken the Finn over the permitted number of some parts for the season.

Mercedes will expect him to be able to fight through the field into a strong points position on a track on which it is relatively easy to overtake.

Renault's Nico Hulkenberg will also start from the back for the same reason.

Ferrari also have their final, upgraded new-spec engine in both cars this weekend.

It was a relatively uneventful session, although Verstappen ran wide through the ultra-fast double-left Pouhon corner towards the end of the session, without causing any damage.

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Behind Hamilton, Ferrari's Kimi Raikkonen, the early pace-setter in the session on a track where he always goes well, was fourth, ahead of Bottas and Red Bull's Daniel Ricciardo, who managed only one flying lap at the end of the session as a result of engine injector problems.

Further back, Lando Norris made an apparently accomplished race weekend debut for McLaren, driving Fernando Alonso's car for this first session.

The 18-year-old Briton had an incident-free session on his way to 18th fastest time on the slowest medium tyre, just under 0.1secs quicker than team-mate Stoffel Vandoorne on the faster soft.

At 7.004km long, Spa is the longest current F1 circuit

However, McLaren's hopes of forming an impression of their relative pace - as they assess who to employ as their second driver following the signing of Carlos Sainz to replace Alonso next season - were dashed because Vandoorne had a session troubled by technical problems.

McLaren sporting director Gil de Ferran said: "We have been investing in Lando for a fair few years and we are trying to give him as much exposure as possible.

"This is an opportunity for him to drive on a grand prix weekend, with a lot more people on the track, a lot of track evolution and a completely different downforce level. We keep walking the development road."

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Esteban Ocon, driving for a Force India team under new ownership after being rescued from administration earlier this month, was best of the rest in seventh.

Hulkenberg, the second Force India of Sergio Perez and Sainz completed the top 10.

Ferrari's Kimi Raikkonen has won four times at the Spa-Francorchamps