Charles Leclerc fastest on the opening morning of Official Pre-Season Test in Bahrain

Ferrari's Charles Leclerc set the fastest time on the morning of Day 1, as the Official Pre-Season Test got underway in Bahrain.

Leclerc's time of 1m 34.531s was the fastest on Thursday morning, Williams' Alex Albon boosting up to second for Williams (+0.54s) with 30 minutes left.

Sebastian Vettel was therefore bumped to third for Aston Martin, ahead of Sergio Perez – who led the mileage stakes for Red Bull (70 laps) on his way to P4 under hot, breezy conditions at Sakhir.

Lewis Hamilton finished fifth, his Mercedes' W13 having turned heads with its diminutive sidepods – the constructors' champions having implemented radical changes from Barcelona to Bahrain.

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That put Alpine's Esteban Ocon sixth, the Frenchman set to make way for Fernando Alonso in the afternoon.

A logistical issue kept Haas garage-bound for the morning, but the team said they were aiming to emerge for the afternoon's four-hour session.

Alfa Romeo encountered an issue after the halfway point, Zhou Guanyu (P7) stopping in the pit lane, but the Chinese rookie emerged with 40 minutes left to add to his lap tally – team mate Valtteri Bottas set to take over to end the day.

McLaren's Daniel Ricciardo sat out the first session due to illness, handing over to Lando Norris – who emerged just before the hour mark and finished eighth, 21 laps to his name, as the team encountered an undisclosed issue.

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AlphaTauri's Pierre Gasly was ninth and last on the leaderboard in the morning, but will continue to run in the afternoon and aim to add to his tally of 44 laps.

Live coverage continues throughout the Official Pre-Season Test, and F1.com will have up-to-date reaction as running continues in Bahrain.

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Coverage of the Official Pre-Season Test is also available live in selected territories via your F1 broadcaster.