The championship leader was in dominant form as he picked up from his victory in Monaco last Sunday to demonstrate that his team and car can adapt to any circuit with imperious authority.
Driving with supreme confidence, Verstappen clocked a best lap in one minute and 14.606 seconds to beat his Mexican title rival by 0.768 seconds, leaving Esteban Ocon of Alpine eight-tenths adrift in third.
On this showing at the Circuit de Catalunya, Verstappen is a clear favourite to increase his 39-point lead ahead of Perez with a fifth win of the year and 40th of his career on Sunday.
Nyck de Vries was fourth for Alpha Tauri ahead of Pierre Gasly in the second Alpine, two-time champion and loudly-supported local hero Fernando Alonso of Aston Martin and Kevin Magnussen of Haas.
Charles Leclerc was eighth ahead of his Ferrari team-mate Carlos Sainz, who has substantial backing at his home event, and Mercedes' George Russell. Seven-time champion Lewis Hamilton was 12th in the second Mercedes.
The session was run in very warm conditions with an air temperature of 26 degrees and the track at 42 as the Red Bull drivers led the way in the opening minutes.
Traded times
Verstappen clocked an early 1:17.425 to set the pace ahead of Perez, by 0.040 seconds, before the pair traded times until the Dutchman reeled off 1:15.945 to pull clear again.
Several drivers were running on Pirelli’s prototype tyre for evaluation, including both Alpines and Sainz. Ferrari had arrived in Spain, as Mercedes did at Monaco a week earlier, with a raft of upgrades including a significant sidepods change.
This saw them running without their 'bathtub' look and adopting a more conventional layout, just days after Mercedes had abandoned their 'zero sidepod' approach to follow the Red Bull approach, as both Aston Martin and others did during 2022.
In effect, it meant that both of Red Bull's main rivals had wasted a year in pursuit of a unique 'ground effect' era design philosophy.
After briefly complaining of 'porpoising', Perez bounced back to go top again before Verstappen clocked a 1:14.606 to ease seven-tenths clear with Magnussen and Gasly in pursuit.
With 15 minutes remaining, it appeared clear that the Red Bulls were in a class of their own and the rest were taking turns to fill third and fourth places, both Alfa Romeos Norris and the Ferraris doing so, like the leaders, on softs.
Leclerc, using the older Ferrari bodywork, was faster than Sainz in the new, but both were a full second adrift of the champion while the Aston Martin and Mercedes men stayed on mediums to test their upgrades.
