Fernando Alonso led the pack out of the pits with a large aerodynamic-load measuring device fitted to the front of his Aston Martin and its new front wing, but it was George Russell who initially set the first-place benchmark at 1m30.214s.
This was, however, almost 10s off the early pace and Russell was quickly shuffled back during the early running – where both Mercedes drivers complained about long brake pedals and the circuit surface gained grip as it cleaned up and had rubber laid down upon it.
The top spot changed hands throughout the opening third of the one-hour session, where only Verstappen, Perez and Leclerc ran the softs from the off, with the rest on mediums.
Perez and Leclerc exchanged quickest times on the red-walled rubber, with the former running an unbroken initial stint, while the latter joined Verstappen in making a trip to the pits for quick adjustments.
Leclerc took his first set of softs back to the top spot on a 1m19.110s at the 15-minute mark, just before Verstappen beat that with a 1m18.670s and a lull in action then followed.
The most notable moments in the next phase were Yuki Tsunoda putting his medium-shod RB in between the two early leaders and Alonso losing the rear of his car through the Turn 10 high-speed right that follows Turn 9 at the end of the meandering, fast walled run from Turn 6 and skating across the exit gravel at high-speed before returning to the pits.
Just before the halfway point, with most of the cars still in the pits during the lull, Norris moved into first place with McLarens first run on the C5 softs, which were barely used by any team during Bahrain pre-season testing, on a 1m18.564s.
Source: Autosport