Leclerc 10-place grid penalty in Abu Dhabi hits Ferrari title hopes
Ferrari are seeking to overturn a 21-point deficit to championship leaders McLaren in Sunday's race, but they suffered a heavy setback when Leclerc was penalised for a new battery pack on his car.
Ferrari are bidding to win the team title for the first time since 2008 and McLaren since 1998.
Leclerc had topped the practice times for Ferrari ahead of McLaren's Lando Norris and Lewis Hamilton, in his final race weekend with Mercedes, in Friday's opening practice.
The Monegasque clocked a best lap in one minute and 24.321 seconds to outpace Norris by 0.221 at the Yas Marina Circuit with Hamilton adrift by four-tenths ahead of Mercedes team-mate George Russell and Alpine's Pierre Gasly.
Nico Hulkenberg was sixth for Haas ahead of Williams' Franco Colapinto, Haas's Kevin Magnussen, Felipe Drugovich who was standing in for Lance Stroll at Aston Martin and Sergio Perez of Red Bull.
Two-time champion Fernando Alonso declared he had "the worst car ever" after clocking the 11th best time in his Aston Martin.
After another episode in the acrimonious fallout between Russell and Max Verstappen, following their spat at last weekend's Qatar Grand Prix, the final opening free practice of the season began in warm sunshine.
Rookies galore
The session involved several rookies including Arthur Leclerc, who lined up alongside his brother Charles for Ferrari – the first brothers to drive together for the same team in an official Formula One session.
At McLaren, Ryo Hirakawa stood in for Oscar Piastri, Isack Hadjar replaced Verstappen at Red Bull, Ayumu Iwasa came in for Yuki Tsunoda at RB and Luke Browning for Alexander Albon at Williams.
Both McLaren and Ferrari used their rookies for aerodynamic testing, but for the Italian team it created a concern as senior driver Charles Leclerc was unable to run, with his car stationary in the garage with a battery problem.
It required a change of battery pack which resulted in a 10-place grid penalty, a blow to Ferrari's hopes before he turned a wheel.
At Alpine, Jack Doohan was brought in for his debut after Esteban Ocon's exit.
The two Mercedes men were quick to set the early pace with Russell leading Hamilton, but complaining that his "cockpit feels very hot", a worry unlikely to be a problem later when second practice takes place.
As the session unfolded, it was confirmed that China had retained its place on the F1 calendar until 2030, days after the Dutch event announced it would not continue beyond 2026.
However, there was no reaction from the International Motoring Federation (FIA) to claims by Russell that Verstappen had threatened to "put me on my (expletive) head in the wall" in Qatar.
On track, Norris went top after 28 minutes following a brief skirmish behind a dawdling Hamilton, who appeared to inadvertently baulk him. The stewards announced an investigation as Hamilton responded by going top in 1:25.566 ahead of Norris.
McLaren then switched to softs and Norris went top with 1:24.524, eight-tenths ahead of Russell, also on softs, before Charles Leclerc finally emerged for Ferrari to lead their pursuit, quickly showing his pace by taking command.
As he clocked his lap in 1:24.321, his brother improved from 20th to 16th with a lap that was two seconds off the pace.