The Red Bulls looked the cars to beat over a single lap during Friday's running and Vettel rammed home their superiority with a time of one minute 37.642 seconds.
There was better news for McLaren following their Friday frustrations. Lewis Hamilton and Jenson Button were second and third, although Hamilton was more than five-tenths off Vettel, with Button adrift by another 0.3 seconds.
Lotus also looked to have found some speed with Romain Grosjean and Kimi Raikkonen fourth and fifth, ahead of the Ferrari of Fernando Alonso.
Alonso, trying to hang on to a four-point championship advantage over Vettel, was a second shy of the German's time, suggesting Ferrari's recent qualifying woes could be set to strike again.
While Vettel dominated it was a frustrating session for his team-mate Mark Webber. The Australian was unable to get out for a run on the super-soft tyres as his mechanics worked on the engine of his RB8 and ended up seventh.
Felipe Massa was eighth with Pastor Maldonado and Nico Hulkenberg rounding out the top 10.
Sergio Perez, who could find himself in trouble with the stewards for blocking Narain Karthikeyan, was 11th ahead of Nico Rosberg and Michael Schumacher in the two Mercedes, who dropped down the order towards the end of the session.
Scotland's Paul Di Resta was 14th for Force India with Kamui Kobayashi next up.
The Toro Rossos of Jean-Eric Vergne and Daniel Ricciardo headed the Williams of Bruno Senna, who lost track time with a front wing issue, with the Caterhams, Marussia's and HRT's rounding out the field.
Despite Vettel's stunning lap, there were some crumbs of comfort for his rivals during the longer runs on the soft tyre early in the session.
While the German was quickest on the harder of the two Pirelli compounds in use this weekend, Hamilton, Button and Alonso all looked stronger in terms of race pace.