Sergio Perez led a Red Bull one-two in final practice at the Belgian GP, before Ferrari's Charles Leclerc narrowly escaped major damage as he crashed into the barriers.
World championship leader Verstappen looked set to repeat his Practice Two dominance until Perez produced a 1:45.047 in the closing moments of the session to better his team-mate by a tenth.
The late flurry of speed from Red Bull, which had also seen Verstappen increase the advantage he had held for much of the session, came after Leclerc once more lost control of his Ferrari to spin through the gravel and make contact with the barrier at Turn 12.
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The Monegasque, whose 80-point deficit to Verstappen in the world championship has largely been caused by errors from both team and driver, managed to keep his car running and made it back to the pits despite red flags immediately being waved.
Perez's late show of strength is particularly significant because Verstappen and Leclerc - along with five other drivers - are facing penalties for taking new engine parts that will see them start from the rear of the grid.
With Mercedes once more off the pace with George Russell sixth and Lewis Hamilton 12th, Perez would appear set for a pole position shootout later on Saturday with Ferrari's Carlos Sainz, who was third.
The third and final practice session was somewhat of a slow burner as the Red Bulls and Ferraris waited until the latter stages to unleash their pace.
Alfa Romeo duo Zhou Guanyu and Valtteri Bottas had topped the timesheet until Sainz and Perez replaced them when finally entering the fray around the halfway point.
It was then Red Bull's turn, with Perez besting the Ferraris by the best part of half a second, before Verstappen went a similar margin clear of his team-mate.
Leclerc, perhaps frustrated by Ferrari's deficit to Red Bull, was then caught out as he pushed too hard into Turn 12.
The incident evoked memories of Leclerc's July crash from the lead of the French GP, which was followed by a haunting scream over team radio.
However, on this occasion, it may prove not to be costly at all, with the car - apart from the front wing - seemingly in good condition as he made his way back to the garage.
When the session resumed for a final few minutes, there was still time for Red Bull to further underline their dominance as both cars improved to leave Sainz almost 0.8s off the lead time.
Lando Norris, who is also starting from the rear of the grid due to taking new parts, was fourth, with Fernando Alonso fifth for Alpine.
It was confirmed during the session that Leclerc, Mick Schumacher and Zhou Guanyu are taking new power units, which means they join Verstappen, Norris and Esteban Ocon in being relegated to the back of the grid.
Valtteri Bottas is facing a 15-place penalty, which means he will start ahead of the other six relegated drivers, whose grid order will be dictated by their qualifying performance.
Watch Belgian Grand Prix qualifying live on Saturday from 2pm on Sky Sports F1.