Charles Leclerc, Verstappen's nearest title challenger, was almost a second off the pace for Ferrari, while McLaren's Lando Norris and Aston Martin's Lance Stroll impressed with third and fourth, respectively.

Carlos Sainz, who had set the pace for Ferrari earlier on Friday as the sport resumed after its three-week summer break, could only manage fifth, while Lewis Hamilton was sixth as Mercedes struggled, with team-mate George Russell in eighth behind Fernando Alonso.

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Verstappen, Leclerc and Norris - along with three more cars - are set to start from the rear of the grid after receiving penalties for taking new engine parts, setting up an intriguing mixed-up grid for Sunday's race.

As had been the case in Practice One, the session's dry running was cut short as showers interrupted the final quarter, but the limited lap time available suggested Red Bull are a step in front of their rivals ahead of Saturday's qualifying.

Ferrari and Mercedes will hope the forecast for warmer and drier conditions over the weekend will enable them to close the apparent advantage that Verstappen displayed on Friday afternoon.

Verstappen unleashes imposing pace

As he had done in Practice One, Verstappen took little time to find his rhythm in the cool and damp conditions in the east of Belgium, going straight to the top of the timesheet

The Dutchman, who holds an 80-point world championship lead going into the final nine races of the season, was momentarily displaced by Ferrari's Carlos Sainz, but this time had a response.

Verstappen quickly re-established his advantage over Sainz, before later setting a 1:45.50, that would ultimately leave him 0.8s clear of Leclerc.

"We just looked at how we set up the car in the best possible way," Verstappen said.

"As soon as we went out the car was working pretty well. After basically the first run I was happy with the car."

Shortly after that rain was in the air, before showers began to all with about 15 minutes remaining of the session.

A few nervous moments followed, most notably for Mick Schumacher as he ran his Haas into the gravel trap at Turn 7, before the field tuned down their aggression as the showers grew heavier.

Sergio Perez continued his recent struggles as he finished 10th after being hampered by DRS and hydraulic issues, but the Mexican will hope to close the near two-second gap to his Red Bull team-mate on Saturday.

Hamilton: Merc a long way off

Having seen Russell take a first pole position of the season for Mercedes in Hungary at the final race before the summer break, the Silver Arrows had arrived in Belgium in buoyant mood, with hopes of adding a first race victory of the season.

In addition, there was speculation that the introduction on tougher controls on the flexing of floors could impact the speed of Red Bull and Ferrari, therefore aiding Mercedes' chances of competing for wins in the final nine races.

However, it was ultimately a highly familiar Friday feeling for Mercedes, with Hamilton and Russell well off the leading pace in both sessions.

"We're just not very quick," Hamilton said. "I don't know why.

"We're going out and giving it everything we've got. It could be tyres, it could be tyre temps, it could be wing level, it could be a multitude of things.

"It doesn't feel disastrous out there, it's just we're a long way off."

The only cause for hope at Mercedes is the fact they have often been significantly behind their rivals on Friday, before being able to make time up throughout the weekend.

Hamilton said: "We often find this on the Friday and then things change a little bit more on the Saturday, so I hope that's the case.

"It doesn't feel the same as it did at the last track in qualifying kind of time, but Friday and Saturday morning it feels kind of similar to that, so that gives me hope that we can turn it round."