Max Verstappen set the benchmark time in the sole practice session for the Qatar Grand Prix ahead of Carlos Sainz and Charles Leclerc.
The Dutchman set his fastest lap of a 1:27.428 late into the session when Red Bull elected to switch both cars to the Soft tyre.
A mistake for Perez in the first sector lost him time to his teammate, and put him over half a second off at the chequered flag in fifth.
The Ferrari drivers followed suit on the Soft in the dying moments of the session, with Sainz 0.334s off the best effort from Verstappen.
Leclerc crossed the line last out of the top three and was 0.147s slower than Sainz, while Alonso was fourth fastest having not set a time on the Soft.
Lewis Hamilton also did not run on the Soft tyre, but struggled to get inside the top ten on the Medium due to the dusty track conditions.
Result Free practice 1 - Qatar
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Track conditions challenging
The newly resurfaced Lusail circuit coupled with the wind blowing sand onto the tarmac proved to be a tricky combination for the drivers.
Initial lap times on the Hard tyre were over 10 seconds slower than the pole lap from 2021, with some drivers remarking that it was very slippery.
A few drivers had snaps of oversteer which put them off track during their laps, while both Lando Norris and Verstappen took out brake marker boards due to oversteer moments on exits of a corner.
Verstappen had another off-track moment in the session when the rear of his usually stable RB19 oversteered at the apex of Turn 6, causing him to catch a slide.
After being among the first to switch to the Soft tyre, Alex Albon ran off track on both timed laps at Turn 4 due to oversteer. He said over team radio that he felt like the rear was not connected to the car and was providing him "zero accommodation" to his engineers.
It is expected to continue throughout the weekend, with the timing of qualifying laps set to be key due to the high track evolution.