San Francisco Frontiers - Norris on top after beating Verstappen in second practice

The 24-year-old Briton, who trails the three-time champion by 84 points in the drivers' title race, clocked a best time of one minute and 17.788 seconds to beat his friend and rival by 0.243 seconds in a tightly-contested session.

Carlos Sainz was third for Ferrari, one-tenth down, ahead of an improving Sergio Perez in the second Red Bull, George Russell of Mercedes and Haas's Kevin Magnussen, who is set to leave the team at the end of the year.

Seven-time champion Lewis Hamilton, hoping to claim a record-increasing ninth Hungarian victory, was seventh ahead of RB's Daniel Ricciardo, Alex Albon of Williams and two-time champion Fernando Alonso of Aston Martin.

Eight different teams were represented in the top ten, signalling how close the field has become –- only Red Bull and Mercedes providing both drivers -– and how a tight race is in prospect for Sunday.

The session began with Nico Hulkenberg leading the way in searing heat amid temperatures of 32 celsius (air) and 60 (track), setting the first lap time on mediums before being usurped by Perez in 1:18.568, the Mexican at last finding some pace.

On his first run, Verstappen complained that his brakes were "not working, they're not biting". He was fifth and then went second behind his Red Bull team-mate.

After a promising first session, Ferrari's fortunes dipped when the luckless Leclerc lost control and ran wide at Turn Four, ran over the kerbs and hit the barriers.

"I touched the wall," he reported, having damaged his car and the advertising hoardings.

The session was red-flagged for 14 minutes before resuming.

For Mercedes, it was also a troubled day following technology problems arising from partner Crowdstrike’s global IT glitch which had resulted in them working with blank screens on the pit-wall during opening practice.

Russell and Hamilton were first out on the re-start with the leading contenders all taking softs for some qualifying simulation runs.

Russell clocked 1:18.294 to go top ahead of Hamilton by 0.069 seconds before Norris took over in 1:17.788, four-tenths clear of Sainz who had set the pace for Ferrari in the opening session until Verstappen slotted into second.

After this flurry of action, most returned to mediums for race preparation while Piastri returned to McLaren for repairs to the floor of his car, his second lengthy absence of the day.

In this period, Perez showed he was back on form in race trim, making it important for him to recover some pure pace in qualifying on Saturday.

"I think this was Sergio’s best Friday performance since China," said Red Bull team chief Christian Horner.

S.Hall--SFF