McLaren’s championship leader Lando Norris topped the timesheets in Thursday’s second practice for the Las Vegas Grand Prix, a session repeatedly interrupted by red flags caused by a loose drain cover on the street circuit.

Running was first halted with around 20 minutes remaining after a marshal reported movement in a manhole cover just before Turn 17. After a 15-minute delay, drivers returned to the track—only for the session to be stopped again with just over two minutes to go when the same cover was found to be shifting under the cars.

The FIA confirmed that trackside personnel had observed continued movement from the manhole cover and ordered the stoppages as a precaution. Loose covers were also a major issue during the inaugural Las Vegas Grand Prix weekend in 2023, when one caused heavy damage to Carlos Sainz’s Ferrari.

Despite the disruption, Norris—who holds a 24-point lead over teammate Oscar Piastri with three rounds remaining—set the fastest lap of the day, a 1:33.602 on soft tyres. That time surpassed Charles Leclerc’s 1:34.802 from the earlier practice session.

“We didn’t manage to get too much from FP2 given the interruptions,” Norris said. “But we did get a slightly better feeling than in FP1. We made some good progress, and there are positives to build on as well as areas to improve for tomorrow.”

Norris had lightly brushed the wall without damage during the opening session, finishing sixth, while Piastri ended FP1 in eighth. The Australian’s second session proved more frustrating—he had to abort a flying lap before the first red flag and never completed a run on softs, leaving him 14th.

Mercedes’ Kimi Antonelli finished FP2 just 0.029 seconds behind Norris, with Ferrari’s Leclerc third before stopping his car with four minutes left. “Something broke—gearbox. Can I shift or not?” he asked on the radio, and was told not to continue.

In the earlier session, Williams’ Alex Albon was second quickest, with Yuki Tsunoda in third and Max Verstappen fourth. The Red Bull star ended FP2 in ninth, having set his time on mediums after running out of laps to switch to softs.

McLaren had warned ahead of the weekend that Las Vegas might be a more challenging venue for them. “I think this could be a tricky weekend,” CEO Zak Brown told Sky Sports during FP1.

The opening session took place on a dusty, low-grip track—typical for temporary street circuits used daily by public traffic—but Leclerc was competitive immediately, while teammate Lewis Hamilton finished only 11th.