San Francisco Frontiers - Verstappen back on top in opening practice at Belgian Grand Prix

The four-time world champion had suffered high-speed crashes at the Austrian and British events in recent weeks and clearly relished running with Red Bull's usual rear wing instead of a much-maligned experimental one he said was very dangerous.

Verstappen clocked a best lap in one minute and 47.070 seconds to outpace seven-time champion Hamilton by 0.145 seconds with Charles Leclerc third in the second Ferrari, ahead of Isack Hadjar in the second Red Bull.

McLaren's Oscar Piastri was fifth ahead of championship leader Kimi Antonelli of Mercedes, world champion Lando Norris in the second McLaren and George Russell in the second Mercedes.

It was the first time this year that neither a Mercedes nor a Ferrari had topped the first session.

In the opening set of laps, it was Red Bull -- having reverted to their original conventional rear wing after ditching the 'Macarena' revolving wing -- who shone with Hadjar, the only man on softs, and then Verstappen, on mediums, setting the early pace.

The Dutchman clocked 1:48.237 to lead by 0.227 seconds after 15 minutes with Hamilton third ahead of Ferrari team-mate Leclerc and Antonelli fifth.

Hadjar, who will start Sunday's race from the back of the grid after Red Bull changed multiple components of his power unit, returned to the top with another fastest lap on softs in 1:47.778 before Mercedes responded.

Having switched to softs, Antonelli clocked 1:47.603 to go top until he was overhauled by Verstappen -- the Dutchman clocking 1:47.070 with Hadjar going second and Leclerc third.

On the longest lap on the calendar, the top five were separated by only half a second as Ferrari emerged as the main threat to Red Bull with 20 minutes remaining.

At that stage, Norris who was on pole last year, was down in 11th for McLaren and facing a 10-place grid penalty after taking a new battery. He soon climbed into the top eight, made up of the 'big four' teams with a clear three-tenths advantage on the rest.

As usual, Aston Martin struggled for pace with Lance Stroll and rookie Jak Crawford, standing in for Spanish two-time champion Fernando Alonso, 21st and 22nd.

Alonso, sitting on the pit-wall, had made clear on Thursday that his "main focus" this weekend was to return home in time to watch Spain play Argentina in the World Cup final.

V.Perez--SFF