Sakhir (Bahrain),  Pierre Gasly of AlphaTauri produced the fastest times on Day 1 of the Official Pre-Season Test here, finishing ahead of Ferrari duo Carlos Sainz and Charles Leclerc.

Leclerc topped the morning timesheets but he finished third overall after conditions cooled and grip improved after the sunset. Gasly capitalised on the improved conditions to set the fastest lap of Day 1 under the lights with an effort of 1m 33.902s. Sainz was second overall.

Although Lance Stroll brought out the first red flag of the day when his Aston Martin jettisoned its aero rakes, the Canadian ended in the fourth position with an afternoon flyer -- finishing ahead of Williams' Alex Albon in P5, according to a report on formula1.com website.

Stroll and Alpine's Fernando Alonso (12th) also enjoyed a duel with 25 minutes of the day remaining, their wheel-to-wheel bout hopefully a sign of things to come for the season-opening Bahrain Grand Prix.

The reports said that McLaren's relatively anonymous showing was improved by a late flying effort from Lando Norris, who took sixth overall.

Valtteri Bottas took P7 in the evening for Alfa Romeo, more than 50 laps under his belt, after teammate Zhou Guanyu (14th) was briefly interrupted by a pit lane stoppage in the morning.

Eighth-place Aston Martin driver Sebastian Vettel set 39 laps in the morning, finishing ahead of George Russell (P9). Mercedes' new recruit took the wheel of the radically redesigned W13 in the afternoon -- his teammate Lewis Hamilton 11th overall, having run in the morning.