Verstappen, the only driver to run for the full day as all other F1 teams split their programmes, put in a 1m32.837s midway through the afternoon to improve on his effort that led the morning session.
It looked nailed on to give Red Bull top spot until a number of teams started to focus on performance runs on the softer compound tyres.
Alonso, on fresh C3 tyres, duly leapt to 0.029 seconds off Verstappen’s benchmark to cap a solid recovery by Aston Martin, after the team’s day endured a false start when Felipe Drugovich – standing in for the injured Lance Stroll – suffered a sensor issue on his first out-lap, which triggered the only red flag of the day.
The Spaniard also lost a chunk of the afternoon session due to floor damage, but recovered sufficiently to log 60 laps to couple up with Drugovich’s 40 laps from the morning.
But Verstappen remained on top by the end of the opening day, having notched up 157 laps in total, to show strong pace and reliability from Red Bull’s RB19 on its first public outing.
Ferrari also enjoyed a decent start to pre-season testing, with Carlos Sainz and Charles Leclerc third and fourth respectively, as the Italian squad comfortably pushed past a century of laps with the SF-23 F1 car.
But one of the teams to struggle on the opening day was McLaren, as Lando Norris lost time, stuck in the garage with the team repairing a wheel fairing issue. But the British driver did recover well to take fifth place on the combined timesheet, six-tenths off Verstappen’s leading effort.
Lewis Hamilton led a solid day for Mercedes in sixth on the final timesheet, as the German manufacturer stuck with its zero-pod design with the W14, while team-mate George Russell dropped to ninth having taken part in the morning session.
Alex Albon took seventh for Williams after debuting the FW45 before handing over to F1 rookie Logan Sargeant for the afternoon, with the US youngster in 10th place.
With Zhou Guanyu in eighth for Alfa Romeo, ahead of team-mate Valtteri Bottas in 12th, F1 returnee Nico Hulkenberg produced an impressive start to his full-time comeback with 11th for Haas and 51 laps to his name – with Kevin Magnussen propping up the timesheet of a field covered by 2.2s.
Nyck de Vries took 13th ahead of his rookie F1 season for AlphaTauri, as Drugovich split him from team-mate Yuki Tsunoda, while Alpine quietly went about its work logging 113 laps with Pierre Gasly and Esteban Ocon 16th and 17th respectively.
Bahrain F1 test day one times
| Cla | Driver | Chassis | Laps | Time | Gap | |
|---|---|---|---|---|---|---|
| 1 |
 Max Verstappen |
Red Bull | 157 | 1'32.837 | ||
| 2 |
 Fernando Alonso |
Aston Martin | 60 | 1'32.866 | 0.029 | |
| 3 |
Carlos Sainz |
Ferrari | 72 | 1'33.253 | 0.416 | |
| 4 |
 Charles Leclerc |
Ferrari | 64 | 1'33.267 | 0.430 | |
| 5 |
 Lando Norris |
McLaren | 40 | 1'33.462 | 0.625 | |
| 6 |
Lewis Hamilton |
Mercedes | 83 | 1'33.508 | 0.671 | |
| 7 |
 Alex Albon |
Williams | 74 | 1'33.671 | 0.834 | |
| 8 |
 Zhou Guanyu |
Alfa Romeo | 67 | 1'33.723 | 0.886 | |
| 9 |
George Russell |
Mercedes | 69 | 1'34.174 | 1.337 | |
| 10 |
 Logan Sargeant |
Williams | 75 | 1'34.324 | 1.487 | |
| 11 |
 Nico Hulkenberg |
Haas | 51 | 1'34.424 | 1.587 | |
| 12 |
 Valtteri Bottas |
Alfa Romeo | 71 | 1'34.558 | 1.721 | |
| 13 |
Nyck de Vries |
AlphaTauri | 85 | 1'34.559 | 1.722 | |
| 14 |
 Felipe Drugovich |
Aston Martin | 40 | 1'34.564 | 1.727 | |
| 15 |
 Yuki Tsunoda |
AlphaTauri | 46 | 1'34.671 | 1.834 | |
| 16 |
 Pierre Gasly |
Alpine | 60 | 1'34.822 | 1.985 | |
| 17 |
Esteban Ocon |
Alpine | 53 | 1'34.871 | 2.034 | |
| 18 |
 Oscar Piastri |
McLaren | 52 | 1'34.888 | 2.051 | |
| 19 |
 Kevin Magnussen |
Haas | 57 | 1'35.087 | 2.250 | |
| View full results | ||||||
