Ferrari's Charles Leclerc will take a 10 place grid penalty at the season-ending Abu Dhabi Grand Prix in a major setback for the team's hopes of a first Formula One constructors' championship since 2008.
Leclerc set the fastest lap in the first practice session at Yas Marina on Friday but Ferrari then revealed they had to change the battery pack on his car, triggering an automatic penalty.
Ferrari are 21 points behind McLaren, last champions in 1998, with 44 still to be won on Sunday.
Leclerc, whose younger brother Arthur was also on track at the same time in the Ferrari usually driven by Carlos Sainz, lapped with a best time of one minute 24.321 seconds.
McLaren's Lando Norris was second fastest in 1:24.542, followed by the Mercedes pair of seven times world champion Lewis Hamilton and George Russell.
Sunday's race will be Hamilton's last for Mercedes before joining Ferrari as Sainz's replacement.
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