San Francisco Frontiers - Norris on top in McLaren 1-2 in final practice

The Briton made the most of Pirelli's new 'super-soft' C6 tyres, designed originally for street circuits, to clock a best lap in one minute and 14.897 seconds and beat Piastri by 0.100 seconds.

For Norris, it was a much-needed riposte to reverse the order of the champion team's drivers after his Australian partner had reeled off four consecutive victories to establish a 16-points lead in the drivers' title race and top both sessions on Friday.

On a day of warm spring sunshine at the Autodromo Enzo e Dino Ferrari, in the Italian team's heartland, McLaren again overcame the best efforts to beat Red Bull's four-time champion Max Verstappen, who was 0.181 seconds adrift in third.

Local hero Kimi Antonelli, born 40km away at Bologna, was fourth in his Mercedes ahead of Ferrari's Charles Leclerc, Carlos Sainz of Williams and rookie Isack Hadjar of Racing Bulls.

George Russell was eighth in the second Mercedes ahead of Alex Albon in the second Williams and seven-time champion Lewis Hamilton in the second Ferrari. Two-time champion Fernando Alsono was an improved 11th for Aston Martin.

Hamilton had warned of brake problems on Friday, suggesting each time he tries a new setting it is a lottery.

"We roll the dice," he said. "We put on one and it works. Another and it doesn’t. We’re working on it!"

His good humour hid his anxiety after six races without a podium finish and he was one of the first men out on Saturday to clock an early time of 1:16.983 ahead of Nico Hulkenberg.

- Unpredictable tyres -

Gasly briefly took control on top of the times, before Hamilton trimmed his lap to 1:15.866 with the usual suspects led by Norris arriving – and moving clear with Verstappen going top after 23 minutes in 1:15.579 ahead of Piastri.

Hamilton was soon pushed down to fourth as Norris rose to second, just 0.077 seconds off Verstappen's pace before the times began to tumble again with Leclerc and then Isack Hadjar going top, the Frenchman in 1:15.529.

At this stage, everyone was running the mediums, Verstappen demonstrating their potential to take command in 1:15.130 ahead of Norris and Hadjar with Leclerc fourth, Piastri fifth and Hamilton sixth.

The track speed progressed in the sunshine and Norris moved closer as others improved before Liam Lawson lost his Racing Bulls car in a high-speed spin at Tamburello, flat-spotting his tyres severely.

With 18 minutes remaining, the teams fitted their C6 'super-softs' in preparation for qualifying and found them difficult to predict with both Piastri and Verstappen aborting flying laps after making mistakes.

Norris, however, showed how it should be done with a lap in 1:14.897 on the suspect softs, which are not expected to prove durable in Sunday's race, taking him top ahead of Verstappen's earlier lap on mediums.

On this evidence, the Grand Prix will provide a strategic and tactical spectacle with unpredictable tyre performance and the onus on driver skill to extract the best from their cars.

After his struggles on Friday, Antonelli made the most of his softs to jump to fourth as others grumbled the softer rubber lacked pace --- with only Norris and Antonelli delivering clean laps before Piastri climbed to second.

B.Ramirez--SFF