Alfa Romeo kicked things off in the second session with a 1:32.355 from Valtteri Bottas.
Alonso was the first of the big guns to do a time with a 1:32.115, followed by Sainz soon after with a 1:31.787.
Moments later, Verstappen did a stonking 1:30.146 to go 0.6s clear of Pérez and 0.9s in front of former teammate Pierre Gasly. Leclerc and Albon completed the top 5 six minutes in.
Ferrari made big gains on their second laps. A 1:29.497 from Leclerc put him a tenth ahead of Verstappen, and he had almost a 0.2s gap to Pérez. Sainz was P3, 0.631s adrift.
The Haas of Kevin Magnussen had a massive spin at the tricky turn 14-15 chicane, brushing the wall but escaping without damage. Lewis Hamilton also had a moment and had to take to the run-off in the same area.
At the front, Verstappen logged a 1:29.380 to reclaim top spot, with Leclerc, Pérez and Sainz following. A mere 0.256s covered the top 4.
Russell, Ocon, Hamilton, Alonso, Gasly and Albon completed the top 10 after seventeen minutes had elapsed.
Using the soft tyres, Lando Norris pumped in a 1:28.741 in the McLaren to go quickest of all. Alex Albon slotted into 3rd, 0.7s off the Brit. Piastri made it a 1-2 for the Woking-based team, although he was almost 0.6s slower than Norris.
The time of the McLaren stood up well, but it was eventually beaten by Verstappen as the two-time World Champion banged in a 1:28.255, almost half a second clear.
He would ultimately lower his benchmark to a 1:27.930 as headrest issues could not stop the 25-year-old from delivering on the circuit.
Photo credit: Red Bull Content Pool
After a tricky weekend for Carlos Sainz in Baku, he finished P2 in the session, 0.385s slower than Verstappen. Leclerc was P3, 0.083s slower than Sainz, but squeezed ahead of Pérez by 0.021s.
Behind the Red Bulls and Ferraris, Alonso was best of the rest in the Aston Martin. Norris, Hamilton, Stroll, Ocon and Albon rounded out the top 10.
Gasly, Magnussen, Guanyu, Bottas, Russell, Piastri, Hülkenberg, Tsunoda, de Vries and Sargeant filled the second half of the timesheets.
On the race simulations, a red flag was thrown with ten minutes remaining as Charles Leclerc crashed in the Ferrari. He had a snap heading into the long left-hander of turns 7 and 8 and ended up in the barriers, breaking his front right suspension.
The Mercedes of George Russell went straight on at turn 11 but continued without any issues.
Right at the end, Sergio Pérez had a big lock-up into turn 1 but got away with it.
