Charles Leclerc topped the opening morning of running in Bahrain, the Ferrari driver clocking in half a second ahead of Williams charger Alex Albon.
Leclerc established the day's first benchmark time of 1m34.531s on the C3 tyre just before the midway point of the session.
Aston Martin's Sebastian Vettel completed the top three, the German concluding his morning 1.175s adrift from Leclerc.
Bahrain Pre-Season Test - Day 1
| Pos | Driver | Team | Time | Tyre | Laps |
|---|---|---|---|---|---|
| 1 | Charles Leclerc | Ferrari | 1m34.531s | C3 | 64 |
| 2 | Alexander Albon | Williams | 1m35.070s | C4 | 53 |
| 3 | Sebastian Vettel | Aston Martin | 1m35.706s | C3 | 38 |
| 4 | Sergio Pérez | Red Bull | 1m35.977s | C3 | 70 |
| 5 | Lewis Hamilton | Mercedes | 1m36.365s | C3 | 62 |
| 6 | Esteban Ocon | Alpine | 1m36.768s | C2 | 42 |
| 7 | Guanyu Zhou | Alfa Romeo | 1m37.164s | C3 | 54 |
| 8 | Lando Norris | McLaren | 1m37.580s | C4 | 21 |
| 9 | Pierre Gasly | AlphaTauri | 1m37.888s | C2 | 44 |
From the outset, all eyes were on Mercedes' updated 'zero sidepod' W13 when cars started to drip out of the pitlane at the started of F1's second round of pre-season testing.
The bold concept turned many heads while Red Bull's Christian Horner was quoted by Auto Motor und Sport as stating that Mercedes had transgressed to spirit of the rules, with the Briton also questioning the car's legality!
Over at Haas, the team's crews were hard at work actively preparing their VF-22 for this afternoon's session, with a freight issue delaying the start of the US outfit's test.
Teams kicked off their running with the usual array of cheese graters and sensors attached to their machines, but the data recording instruments were gradually shed, and drivers picked up the pace.
Leclerc headed into the second hour of the day with the fastest lap, the Monegasque's benchmark 1m35.953s being seven seconds off last year's pole time at Sakhir.
However, the Ferrari driver, shod with Pirelli's mid-range C3 compound, went faster still, shaving 1.4s off his initial flyer. The lap was also 1.8s faster than Hamilton's second-best time.
Leclerc attempted to outdo himself in the final hour before the lunch break, but to no avail. The Scuderia charger nevertheless concluded the morning segment of Thursday's session comfortably ahead.
However, with 67 laps under his belt, the Monegasque was out-distanced by Red Bull's Perez who topped the lap count with 70 laps.
A productive session for Alex Albon allowed the new Williams driver to set the second fastest time, just ahead of Aston Martin's Sebastian Vettel.
Behind Perez in fourth position, Hamilton was fifth, the Briton working diligently through Mercedes' programmes.
Further back, Alpine appeared to have solved the DRS issue that had impacted its test in Spain, with Esteban Ocon clocking in P6, ahead of Alfa rookie Zhou Guanyu who stopped in the pitlane at one point and had to be pushed back to his garage.
An apparent brake issue limited McLaren's running, with Lando Norris putting just 21 laps on the board and setting the eighth quickest lap.
Finally, AlphaTauri's Pierre Gasly was the slowest of the nine drivers to set a time, with a lap that left him 3.357s off Leclerc’s best.
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