Verstappen set his headline time halfway through FP1 as the Red Bulls proved to be on the pace straight away, and looked untouchable in a warning shot to his rivals as they hope to end the Milton Keynes squad's monopoly on race wins in 2023.
This was F1's first session at the Circuit de Barcelona-Catalunya without the much-derided final chicane since 2006, making Fernando Alonso the only driver to have competed with the original final two corners.
Alonso was the first driver to hit the road in the session, much to the delight of the home fans, and carried two front-end-mounted aero rakes on his exploratory laps to assess the airflow patterns behind the front wheels.
This came amid most of the cars running a prototype Pirelli construction, developed in response to escalating loads produced by the F1 cars. This is set to be introduced for the British Grand Prix.
Max Verstappen was top of the times after the opening five minutes of the session on the new C1 construction, setting a 1m17.425s to chisel Red Bull team-mate Sergio Perez off top spot.
He then logged a 1m16.583s just as Perez had got to within 0.04s of the Dutchman's previous lap, to extend his advantage to over eight-tenths of a second.
The Red Bulls then switched to the medium tyre, Perez posting a 1m16.420s before Verstappen overhauled his team-mate with a 1m15.945s, and was a second and a half clear of Nico Hulkenberg in third as the Haas driver opened his session on the soft tyre.
Perez and Verstappen were reporting bouncing in the final corner, something that had also afflicted Mercedes' George Russell and McLaren's Lando Norris in the early phases as they got to grips with the revised third sector.
Carlos Sainz then put his car into the top three after the opening 20 minutes had elapsed as the Ferraris ran in a split specification during the session; Charles Leclerc ran the old sidepods to contrast with Sainz running the new package to ensure the team had data on both.
Sainz was soon displaced from third by Alonso, but Pierre Gasly then denied both a place in the top three as he moved up to second-fastest, splitting the two Red Bulls as he was 0.418s off the best time.
The Red Bulls then bolted on the soft tyres for the second half-hour, Perez kicking off their efforts on the red-walled tyre with a 1m15.374s to briefly lead the session. Verstappen then hammered in a 1m14.606s to go nearly 0.8s quicker than his team-mate.
Red Bull's early efforts were perhaps in anticipation of getting the bulk of running in early on, as dark clouds loomed large over the track - but no rain ultimately fell during the course of the hour-long session.
Those times went largely unchallenged over the next 20 minutes; although the Ferraris got slightly closer with their own soft-tyre efforts, they were a second away from Verstappen's headline effort.
Nyck de Vries then outpaced them to move up to third, where he remained for the next three minutes until Monaco podium finisher Esteban Ocon slotted his Alpine in ahead, getting to half a tenth of Perez's best effort.
Pierre Gasly was fifth fastest as the Alpines continued to look strong, albeit coming to blows at Turn 10 late on in the session when trying to launch a pass on Williams' Logan Sargeant.
Kevin Magnussen had fired his Haas up to sixth, ahead of the Ferraris, in the final three minutes of the session as the drivers collected their last orders prior to the chequered flag. The Dane was then relegated down a spot as Alonso put in a time good enough for sixth.
Leclerc and Sainz were eighth and ninth fastest, as Russell completed the top 10 as Mercedes endured a relatively quiet session overall.
Norris split the Mercedes after slotting into 11th, the McLaren team continuing to run its Triple Crown special livery for the Spanish Grand Prix.
F1 Spanish Grand Prix FP1 Results:
| Cla | Driver | Chassis | Engine | Time | Gap | |
|---|---|---|---|---|---|---|
| 1 |
 Max Verstappen |
 |
Red Bull | Red Bull | 1'14.606 | |
| 2 |
 Sergio Perez |
 |
Red Bull | Red Bull | 1'15.374 | 0.768 |
| 3 |
 Esteban Ocon |
 |
Alpine | Renault | 1'15.418 | 0.812 |
| 4 |
Nyck de Vries |
 |
AlphaTauri | Red Bull | 1'15.504 | 0.898 |
| 5 |
Pierre Gasly |
 |
Alpine | Renault | 1'15.545 | 0.939 |
| 6 |
 Fernando Alonso |
 |
Aston Martin | Mercedes | 1'15.547 | 0.941 |
| 7 |
 Kevin Magnussen |
 |
Haas | Ferrari | 1'15.689 | 1.083 |
| 8 |
 Charles Leclerc |
 |
Ferrari | Ferrari | 1'15.694 | 1.088 |
| 9 |
Carlos Sainz |
 |
Ferrari | Ferrari | 1'15.726 | 1.120 |
| 10 |
 George Russell |
 |
Mercedes | Mercedes | 1'15.753 | 1.147 |
| 11 |
Lando Norris |
 |
McLaren | Mercedes | 1'15.783 | 1.177 |
| 12 |
Lewis Hamilton |
 |
Mercedes | Mercedes | 1'15.845 | 1.239 |
| 13 |
 Zhou Guanyu |
 |
Alfa Romeo | Ferrari | 1'15.906 | 1.300 |
| 14 |
 Yuki Tsunoda |
 |
AlphaTauri | Red Bull | 1'15.915 | 1.309 |
| 15 |
 Lance Stroll |
 |
Aston Martin | Mercedes | 1'15.939 | 1.333 |
| 16 |
 Valtteri Bottas |
 |
Alfa Romeo | Ferrari | 1'15.978 | 1.372 |
| 17 |
 Oscar Piastri |
 |
McLaren | Mercedes | 1'16.353 | 1.747 |
| 18 |
 Nico Hulkenberg |
|
Haas | Ferrari | 1'16.461 | 1.855 |
| 19 |
 Logan Sargeant |
 |
Williams | Mercedes | 1'16.506 | 1.900 |
| 20 |
 Alex Albon |
 |
Williams | Mercedes | 1'16.630 | 2.024 |
| View full results | ||||||
