MANAMA — Title favorite Lando Norris was fastest for Formula One champion McLaren after a power cut disrupted the first day of preseason testing in Bahrain on Wednesday.

The session was extended by an hour into the evening after the outage, caused by a substation failure, plunged garages into darkness with engineers using torches as mechanics connected back-up generators.

"I came to the pits and said 'it's dark out here. I need to change my visor'. Then I realized there are no floodlights around," Mercedes' George Russell told Sky Sports television.

"It would have been hectic if this was an hour later and the sun had already set."

Seven-time world champion Lewis Hamilton had already done 70 laps, more than a full race distance, as he started official testing for Ferrari after his move from Mercedes at the end of last year.

The 40-year-old Briton, chasing a record eighth title in 2025, was fifth fastest in a morning session led by his Mercedes replacement, 18-year-old Italian Andrea Kimi Antonelli.

"Our focus right now is on experimenting with different things, gathering as much data as possible and getting familiar with the car, and we've already learned a lot," said Hamilton.

"It's too early to really understand performance, but everything feels good."

Charles Leclerc took over the car after lunch and was fourth overall.

Norris, last year's runner-up to Red Bull's four-time world champion Max Verstappen and now the bookmakers' favorite, said it was nice to be back in the car after setting a day's best time of one minute 30.430 seconds.

"It was a good, fun day on track, and we progressed through a lot of the tests that we wanted to do. I'm looking forward to pushing the car a bit more over the next couple of days," he said.

Hamilton's replacement Antonelli, 18, was the first on track and did 78 laps with a morning best of 1:31.428 on the medium tyres.

He handed over to Russell, who was second fastest with 69 laps and ahead of Verstappen (74 laps).

"We don't know pace yet but everything is working well and the car is doing what I want it to do. It is all in control and that is what we can hope for really to start my testing," said Verstappen.

New Zealander Liam Lawson, Verstappen's new teammate, spun the new RB21 in the morning but was second fastest (58 laps) in that session with Williams' Alex Albon third (63 laps).

Albon's new teammate Carlos Sainz, who has joined from Ferrari, was fifth fastest and did 68 laps.

Racing Bulls' Yuki Tsunoda, fourth on the timesheets, matched Antonelli's 78 lap tally, with British rookie Oliver Bearman completing 72 for Haas.

Reuters