"This pole is the perfect answer to the stupid penalty I was given yesterday," said a thrilled Deletraz.
"This is a great result for Renault; I'm good friends with Jack, we're on the programme together, and I'm pleased for him."
Aitken was quickest midway through the half hour session, his best time set on used tyres, before being stripped of his that lap for a track limits infringement at Turn 10.
The RP Motorsport driver - who qualified on pole for Saturday's first race - was relegated to the back of the field, but moved back onto provisional pole entering the final two minutes of qualifying before Deletraz's late improvement.
"I know just where I lost those three thousandths of a second," said Aitken.
"After losing my first lap, I was being extra careful through Turn 10, and probably gave up a good tenth there."
Race one winner Matevos Isaakyan continued his strong form to qualify third for SMP Racing, ahead of team-mate Matthieu Vaxiviere.
Egor Orudzhev ended the morning as the leading Arden runner in fifth, and will be joined on the third row by Beitske Visser.
Championship leader Dillmann had tough session and will start Sunday afternoon's race from 13th, one place behind AVF team-mate and Force India Formula 1 Friday driver Alfonso Celis Jr.
Charouz-run Lotus driver Rene Binder will start from the last row after spinning off on the exit of Turn 2 eight minutes into qualifying and lightly damaging his car.
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