Before the one-hour session really got going, it was suspended when Perez crashed on his first timed lap on the medium tyres – the field split across running that compound and the softs at this stage.
With two minutes completed and before anyone had set a time, Perez lost control of his RB19 after dipping his left-rear on the outside grass through the long right of Turn 5.
It snapped away from him in a full 360-degree spin and speared into the wall on the outside, which damaged the newly upgraded sidepods on its left side, as well as both front corners.
The session was suspended for eight minutes by red flags as the Red Bull was recovered, after which most of the pack headed back out again, but conditions had quickly changed with the rain coming down.
Kevin Magnussen was set to produce the first timed lap while running the mediums, but as he reached the final turns where the rain was falling heaviest, he came across Valtteri Bottas recovering from a spin in his Alfa Romeo and all the cars then piled back into the pits.
That led to a lengthy lull in action – other than single exploratory laps for Lewis Hamilton, Esteban Ocon, Carlos Sainz and Alex Albon, with Ferrari driver Sainz having moments at the Turns 6/7 chicane at the Turn 12 right at the start of the third sector before he pitted.
Charles Leclerc ventured out just before the halfway point before he too pitted, shortly after which McLaren sent both Lando Norris and Oscar Piastri out, just as the rain got heavier.
Source: Autosport