Leclerc was 0.099 seconds quicker than Red Bull's Isack Hadjar, with McLaren's Lando Norris third fastest, 0.137secs off the pace.

But divining a sense of real competitiveness was made even more difficult than usual because of the varying strategies teams deployed through practice.

Neither Hadjar nor team-mate Max Verstappen completed a qualifying simulation run on the soft tyre.

But Verstappen, who was fourth fastest overall behind McLaren's Lando Norris, looked potentially the fastest driver through practice until the single laps took place in the second session.

At the same time, Ferrari looked especially impressive on the race-simulation runs.

But these were also difficult to read, as there was an even split between the teams as to whether they ran the soft or medium tyres.

Mercedes drivers George Russell and Kimi Antonelli, whose car has a major upgrade this weekend, were only seventh and eighth fastest - and it would be a major surprise if they qualified there.

Racing Bulls' Liam Lawson and Alpine's Pierre Gasly were ninth and 10th.

Three drivers have grid penalties. Hadjar will drop five places from his qualifying position for exceeding the permitted number of engine parts.

And Arvid Lindblad of Racing Bulls and Alpine's Franco Colapinto will be at the back, the Briton for engine penalties, and the Argentine because of a 10-place engine penalty on top of the five-place penalty he was given for causing a crash at a restart in last weekend's Azerbaijan Grand Prix.

F1 has returned to the Sepang track, regarded as one of the best layouts among the new generation of circuits that came on stream at the end of the last century and into this one, because of the circumstances around this year's calendar.

The Bahrain and Saudi Arabia races were cancelled at the beginning of the year as a result of the war in the Middle East.

But Bahrain were keen to hold their race and Crown Prince Salman bin Hamad bin Isa Al Khalifa negotiated to hold the race in Malaysia.

A bunch of Bahraini-related activities are being held at the track, while the trophy presented will be the Bahrain Grand Prix trophy and rosewater rather than champagne will be sprayed on the podium.