Calado produced a phenomenal performance in the 30-minute session, putting in two laps good enough for pole position within 0.005 seconds of each other.
His strategy of running first on the soft tyre, as opposed to the super-soft, paid dividends and his opening gambit of 1m47.347s was soon followed up by a 1m47.342s lap on the same rubber.
Calado ended the session 0.007s clear of Felipe Nasr of DAMS, and even found time for a quick spin on his final run on super-softs, on which he did not improve.
Calado's team-mate Esteban Gutierrez was third quickest, a tenth off pole position, with points leader Davide Valsecchi (DAMS) fourth. Valsecchi opted to run on super-softs from the start, but his cause was not helped when the session was interrupted before it had properly begun, when Lazarus' Giancarlo Serenelli spun at Turn 8 - the corner before the bridge - and brought out the red flags just as he was starting a flier.
Valsecchi eventually produced a 1m44.458s, but his efforts to improve that on soft tyres in the closing moments were dashed by tailenders Fabrizio Crestani (Lazarus) and Rodolfo Gonzalez (Caterham) squabbling over track position, and he was forced to abort.
Giedo van der Garde will start fifth for Caterham, ahead of Carlin's Max Chilton and Racing Engineering's Fabio Leimer - both of whom set their fastest times on super-softs, which bucked the trend of the majority.
iSport duo Jolyon Palmer and Marcus Ericsson were only eighth and ninth fastest, despite impressing in practice this morning, while points runner-up Luiz Razia of Arden will start down in 11th. He suffered a lurid slide when he locked-up at Turn 1 as he tried in vain to improve.