Charles Leclerc completed a practice sweep as Ferrari upped the ante in the final session.
Completing a series of short runs before qualifying, the Monegasque pumped in a 1m41.604s on the Soft tyre to take the top spot.
Teammate Sebastian Vettel would have to abandon his first effort having gone too deep into Turn 1 but would close to within 0.2s in P2 thanks to a big slipstream in the final sector.
Max Verstappen surprised with a strong lap for third place in the Red Bull, albeit 1.2s off the pace set by Leclerc.
With Mercedes also struggling to get a clean lap in as Valtteri Bottas and Lewis Hamilton sat fourth and fifth.
In the midfield, Toro Rosso is leading a very close fight as Daniil Kvyat finished sixth with teammate Alex Albon in eighth.
The single lap pace of the Haas has also brought them back into contention after Kevin Magnussen took seventh.
All three cars were covered by less than a tenth before a slightly larger gap back to Baku specialist Sergio Perez in ninth for Racing Point.
Mr Dependable Kimi Raikkonen completed the top 10 for Alfa Romeo.
With the slipstream being so powerful on the main straight and mistakes still particularly easy to make, one good lap with a bit of luck will make all the difference.
Therefore, Daniel Ricciardo in 11th, Antonio Giovinazzi in 12th and the two McLaren’s following can all consider themselves in with a shout of Q3.
Particularly Carlos Sainz, who came across cars at just the wrong point during his warm-up and flying laps, leaving the Spaniard down in 14th.
Behind that, the likes of Nico Hulkenberg, Lance Stroll and Romain Grosjean are set to duel to avoid Q1 elimination.
But only one place might be unfortunate as both Williams remain stuck at the bottom of the times, Pierre Gasly is already guaranteed a pit-lane start and Antonio Giovinazzi will take a 10-place grid drop for a new engine component.
Full results from a rare incident-free final practice in Azerbaijan can be seen below:
