Sette Camara set his best lap in the final ten minutes of the session, displacing de Vries with a 1:44.009. De Vries' best time was a long way off, with the gap reading six-tenths.
Championship leader Nicholas Latifi, who took part in the Formula 1 free practice one session in the morning, struggled for pace, ending up one second down on teammate Sette Camara.
Latifi also spun during the session, while Nikita Mazepin ended the session facing the wrong way at the chicane along the Mistral Straight, stalling his car when the chequered flag was waving.
Luca Ghiotto was third for Uni Virtuosi, half a tenth behind Dutchman Nyck de Vries, while the Ferrari Drivers' Academy duo of Mick Schumacher and Callum Ilott followed in fourth and fifth respectively
It was a tricky session for MP Motorsport and BWT Arden, who ended up filling out the final four slots.
Jordan King was 17th, returning after his adventure at the Indianapolis 500. He headed Anthoine Hubert and Tatiana Calderon while rounding out the timesheets was Mahaveer Raghunathan - 7.9 seconds off the pace.
Bahrain International Circuit - Winter testing