Il Nuovo Postiglione - Norris tops red-flagged second practice for Las Vegas GP

The Briton, who boasts a 24-point lead over teammate Oscar Piastri in the drivers standings entering Sunday's race, completed his hot lap just before crimson fury struck the Las Vegas Strip.

Norris was quickest around the 6.201-km street circuit with a lap of 1min 33.602secs -- 0.029sec ahead of Mercedes' Kimi Antonelli.

Moments later, the session was red-flagged for a possible loose manhole cover.

Cars returned to the track with six minutes remaining, time enough for Charles Leclerc of Ferrari to end his session behind a safety barrier due to a gearbox issue, before a final red flag concluded the session early.

Monaco's Leclerc was third in a session where many of the drivers did not have a soft tyre run, including Piastri, who was 14th and 0.891 adrift of title rival Norris.

Australian Piastri, who was 34 points clear in the standings after winning the Dutch Grand Prix in August, has not managed a podium finish in the past five races.

While Norris cannot secure the world championship crown this weekend, he could doom the repeat bid of four-time defending champion Max Verstappen, the Dutchman entering 49 points adrift.

Verstappen was ninth in the second session, 0.503 off the pace.

Leclerc set the fastest time in first practice in 1:34.802 with Thailand's Alexander Albon second for Williams and Japan's Yuki Tsunoda of Red Bull third.

A lack of grip marked the opening session on the Las Vegas strip as many cars skidded or failed to brake in some corners, Norris touching a wall in an incident without consequences.

E.Spicuzza--INP