In an opening session with one red flag interruption caused by an early on-track stoppage for Aston Martin's Felipe Drugovich, who is standing in for the injured Lance Stroll, reigning world champion Verstappen traded best lap times with Ferrari's Carlos Sainz.
Sainz's 1m33.253s led for the majority of the morning but was beaten by Verstappen's 1m32.959s set 35 minutes before the lunch interval.
All teams enjoyed productive running, as only Drugovich lost a significant amount of track time due to what the team called a sensor issue related to the ECU, with the relatively stable technical regulations allowing teams to get up to speed quickly with their 2023 F1 cars.
To underline that point, the majority of squads completed over a grand prix distance on the opening morning, primarily focused on data collection, aero runs and installation work.
Verstappen, whose leading lap time was almost a full second quicker than the best lap set on the opening day of last year's Bahrain test, ended the morning nearly three tenths faster than Ferrari's Sainz.
Williams topped the lap count charts for the morning with Alex Albon on 74 laps, with the Thai driver also taking third place on the timesheet with a 1m33.671s, ahead of Zhou Guanyu in the Alfa Romeo who took fourth.
George Russell, who was first on track this morning, slotted into fifth for Mercedes which put the German manufacturer 1.2s off the outright pace.
F1 returnee Nico Hulkenberg also enjoyed a solid morning for his new team Haas with sixth place, a quarter of a second off Russell, as Drugovich popped in a late lap to move up to seventh place on the times for Aston Martin.
AlphaTauri's Yuki Tsunoda posted 46 laps in the session on his way to eighth place in the times, ahead of former teammate Pierre Gasly who notched up 60 laps for Alpine.
F1 rookie Oscar Piastri began his season with 52 laps for McLaren as he rounded out the morning timesheet in 10th place.
Nine of the 10 teams will switch drivers for the afternoon session, except Red Bull as world champion Verstappen gets the full opening day in the RB19.
| Position | Driver | Car | Time | Laps | Gap |
|---|---|---|---|---|---|
| 1 | Max Verstappen | Red Bull | 1'32.959 | 71 | |
| 2 | Carlos Sainz | Ferrari | 1'33.253 | 72 | +0.294s |
| 3 | Alexander Albon | Williams | 1'33.671 | 74 | +0.712s |
| 4 | Zhou Guanyu | Alfa Romeo | 1'33.723 | 67 | +0.764s |
| 5 | George Russell | Mercedes | 1'34.174 | 69 | +1.215s |
| 6 | Nico Hulkenberg | Haas | 1'34.424 | 51 | +1.465s |
| 7 | Felipe Drugovich | Aston Martin | 1'34.564 | 40 | +1.605s |
| 8 | Yuki Tsunoda | AlphaTauri | 1'34.671 | 46 | +1.712s |
| 9 | Pierre Gasly | Alpine | 1'34.822 | 60 | +1.863s |
| 10 | Oscar Piastri | McLaren | 1'34.888 | 52 | +1.929s |
