SAKHIR, Bahrain (AFP) — Lewis Hamilton topped the times ahead of his Mercedes teammate George Russell in Thursday's second practice for this weekend's Bahrain Grand Prix as defending champion Max Verstappen struggled to sixth.

In an unexpected surge of pace that was not expected following their two years of struggle in the ground-effect era, the 'Silver Arrows'' were dominant ahead of two-time champion Fernando Alonso of Aston Martin.

Hamilton clocked a best lap of 1min 30.374sec to outpace Russell by two-tenths under the lights at the Bahrain International Circuit at Sakhir.

Alonso was third ahead of Carlos Sainz, whose Ferrari seat will be taken by Hamilton next year, with McLaren's Oscar Piastri fifth ahead of Red Bull's Verstappen and Nico Hulkenberg of Haas.

Lance Stroll was eighth in the second Aston Martin ahead of Charles Leclerc in the second Ferrari and Sergio Perez in the other Red Bull. The fuel loads and engine settings of the teams remained unknown, but it was clear — even in gusty conditions — that Mercedes' car for 2024 was much different in performance and potential to the 'diva' of previous years.

Zhou Guanyu was first out for the session in his eye-catching green and black Sauber ahead of a group of rivals before Leclerc took control in his Ferrari, topping the times with a lap in 1:31.578.

That did not last long before Hamilton showed the potential of the new Mercedes to clock 1:30.751 and set the pace with team-mate Russell while Verstappen, frustrated by car and conditions, worked up to third.

"I've got too much air into my helmet" complained the Dutchman, running on softs like everyone else.

Hamilton, who has not won in 45 races — he won 22 of the 45 he entered before that, continued to improve and after half an hour clocked a new fastest lap in 1:30.374, moving four-tenths clear of nearest rival Sainz, whose seat at Ferrari he takes next season.

Both Red Bulls were struggling to match the pace on softs at this stage and Russell endorsed the view that Mercedes is back in contention when he went second with 25 minutes to go. That signalled a switch in focus to race set -up lapping for most teams, all switching to run on used tyres for data collection ahead of Saturday's race.

In this phase, Verstappen's lap times were impressive and appeared to show less reaction to tyre wear in the conditions.

Daniel Ricciardo, who topped the times for the re-branded RB team, formerly Alpha Tauri, in Thursday's first practice, ended up in 12th.