Newly crowned world champion Lewis Hamilton set the pace in a subdued opening practice session at the Bahrain Grand Prix.

Overcast skies and occasional spots of rain made for very un-desert like conditions in the Middle East, but the daytime session still wasn't considered representative to what drivers will face under the lights come qualifying and the race.

As a result, teams focused primarily on aero and tyre evaluation work as Pirelli provided two sets of the C3 compound which will be used in 2021.

Still, it didn't stop Mercedes reclaiming their place at the top of the timesheets after giving it up in Turkey, at least until race day.

Hamilton led the way with a 1m29.033s on the medium compound, four-tenths clear of teammate Valtteri Bottas.

The main issue for the Finn though was braking with at least four lock-ups during the 90 minutes.

Sergio Perez claimed third for Racing Point, ahead of Carlos Sainz and Pierre Gasly in fourth and fifth.

Max Verstappen was down in sixth for Red Bull on the soft tyre, just 0.008s ahead of teammate Alex Albon in seventh.

The Dutchman was less than impressed with Pirelli's new tyre too, spinning at the final corner and complaining of understeer during his stint.

Esteban Ocon was a late improver to eighth ahead of Lance Stroll and Renault teammate Daniel Ricciardo, who completed the top 10.

Ferrari's lack of straight-line speed may already be proving a hindrance in the tight midfield fight with Charles Leclerc only 11th and Sebastian Vettel 12th.

Alfa Romeo reserve Robert Kubica returned to the cockpit for FP1, and finished almost two-tenths faster than Antonio Giovinazzi in 13th, with the Italian down in 16th.

The two Haas cars were in-between in 14th and 15th with Romain Grosjean ahead, this after surviving a scary moment through Turn 6 after losing the rear over the kerb.

Daniil Kvyat had his best time deleted for track limits, dropping the Russian back to 17th, while Lando Norris also had a difficult session in 18th for McLaren.

The two Williams' brought up the field as Nicholas Latifi finished three-tenths ahead of development driver Roy Nissany.

While the order may prove unrepresentative, it was certainly a tight session as less than a second covered Perez in P3 to Giovinazzi in P16.

So it will be interesting to see how things shake up under the lights in Practice 2.

Full results from Practice 1 can be seen below: