Those who ran in Wednesday’s first session, when track conditions were hotter and slower, were at an immediate disadvantage when it came to outright lap time.
Ferrari’s Charles Leclerc and Aston Martin’s Fernando Alonso, second and third behind Verstappen at the lunch break, still finished the day in overall seventh and eighth places though, despite handing their cars over to their team-mates at the lunch break.
However, Verstappen looked almost as strong in the morning as he proved in the afternoon – Leclerc was 0.8secs off his pace, Alonso less than 0.1secs further back.
Sainz had just 0.015secs on Daniel Ricciardo – driving for Red Bull’s second team, now known as RB. Alpine’s Pierre Gasly was fifth fastest, followed by Aston Martin’s Lance Stroll.
Mercedes, for whom George Russell was only 12th fastest, spent the first session working on bigger set-up changes, including on the floor, and then did long runs on harder tyres in the second, eschewing the single-lap runs completed by many rivals. Lewis Hamilton did not drive on Wednesday.
It was a difficult day for Williams. Their car was the last to take to the track for an initial shakedown test, running only the day before testing started, while all other teams had been out previously.
Logan Sargeant was 11th fastest but managed only 21 laps, punctuated with a spin at Turn Nine, before driveshaft problems ended his running.
Team-mate Alex Albon, who drove in the first session, completed 40 laps but stopped early with a fuel-pump failure.