Williams driver Alex Albon was third fastest, with team-mate Logan Sargeant fifth behind Red Bull’s Sergio Perez.
Mercedes had a difficult day, George Russell and Lewis Hamilton down in 12th and 15th despite a new front wing.
Lando Norris was 14th fastest in the upgraded McLaren that impressed so much last weekend in Austria.
Ferrari’s Charles Leclerc did not get out in the session at all after the team discovered an electrical problem over the lunch break.
Fernando Alonso, third in the championship for Aston Martin, was only 10th fastest on single-lap pace, with team-mate Lance Stroll sixth, ahead of the Haas of Nico Hulkenberg, Pierre Gasly’s Alpine and McLaren’s Oscar Piastri.
Piastri, an Australian who is in his debut season, has on his car for the first time the upgrade that Norris debuted in Austria, while Norris has those parts in addition to a new front wing.
Verstappen, who was also fastest in the first session, was in imposing form. While his single-lap pace was not far clear of the Ferrari of Sainz, the world champion was in a league of his own on long-run pace.
His race-simulation run was more than 0.5secs a lap on average quicker on the same soft tyre than Perez, with Sainz a little further behind.
Hamilton, despite his struggles over one lap, appeared in much better shape on a long run, running at around the same pace as Perez.
The Williams pace was a surprise, but although the team have made conspicuous progress with an upgrade to the car added in Canada two races ago, third and fifth for Albon and Sargeant is an over-achievement.
The British-born Thai and his American rookie team-mate must be considered unlikely to be that competitive come Saturday.
As the session ended, Hollywood star Brad Pitt was preparing to take to the track in a modified Formula 2 car, the first race at which filming will take place for the new Apple F1 movie.
The Oscar winner, who has been practising at Silverstone in the lead up to the race, is playing a veteran racer called Sonny Hayes who returns to the sport to mentor a rising young star.
The film crew are operating out of their own garage at Silverstone and will continue their work at a number of races over the rest of the season.
