San Francisco Frontiers - Norris on top as McLaren dominate opening Sao Paulo practice

Norris clocked a best lap of one minute and 9.975 seconds to beat the Australian by just 0.023 seconds, the pair of them six-tenths clear of third-placed Nico Hulkenberg of Haas.

Two-time champion Fernando Alonso of Aston Martin was fourth ahead of Sauber's Gabriel Bortoleto, Mercedes' George Russell, Pierre Gasly of Alpine and Carlos Sainz of Williams.

Isack Hadjar was ninth for Racing Bulls and Kimi Antonelli 10th in the second Mercedes.

Max Verstappen was 17th for Red Bull after running only on hards and using the session for data acquisition.

The two Ferraris of Charles Leclerc and seven-time champion Lewis Hamilton wound up 18th and 19th ahead of Red Bull's Yuki Tsunoda. The Ferraris ran the whole session on hard tyres without switching to softs in the final laps.

Hamilton also had a big spin at Turn 11 in the final minutes as the flag came out. "Rear hit the floor," he reported, suggesting that Ferrari were attempting to run a minimal ride-height on the bumpy Interlagos circuit.

It was a busy and eventful session which offered a strong clue to McLaren's adaptation for the circuit but without any clear signals of what else to expect ahead of sprint race qualifying later Friday. Most of the teams switched to mediums to clock their best laps.

The two Mercedes led the way out to start the session on a bright sunlit day before Alonso and then Piastri topped the early times, just hours after Alpine had confirmed that Franco Colapinto was to remain with them next year.

Russell was soon on top and reacted to a faster lap by Norris to return with a best of 1:11.542 after 16 minutes as he lapped increasingly quickly to cut his lap time to 1:11.188 before pitting after a 10-lap stint.

Verstappen ran off at Turn Four in similar fashion to Tsunoda, earlier in the session, suggesting Red Bull were facing a challenge as teams began switching tyres to evaluate in the only practice session of the weekend.

The times remained unchanged for a period before Albon went top only for Russell to reply and then be trumped by Sainz in 1:10.820 on mediums before the McLarens showed their potential in the final minutes.

On his final lap Piastri went top with seconds remaining before Norris beat him by 0.023 ahead of Hulkenberg, who 15 years earlier on this day, had claimed the only pole position of his career.

A.Smith--SFF