Antonio Giovinazzi snatched Spa GP2 pole from Prema team-mate Pierre Gasly in the closing moments of qualifying, while championship leader Sergey Sirotkin ended up 13th.
Gasly had been on provisional pole after the first runs with a 1m57.068s, and then improved to 1m56.768s later in the half-hour session.
That initially looked like it would be enough, but rookie Giovinazzi produced a lap 0.161 seconds faster to steal pole away, as Prema took its first front-row sweep in GP2.
Gusta Malja went out earlier than most for his second runs and it paid off as he jumped to a temporary second before ending up a career-best third for Rapax.
Racing Engineering team-mates Norman Nato and Jordan King were next up, followed by Malja's stablemate Arthur Pic.
Raffaele Marciello, Alex Lynn, Nobuharu Matsushita and Marvin Kirchhofer completed the top 10.
Sirotkin's session didn't begin well, as he ran wide on his first flying lap and then had a huge lock-up into the Bus Stop on his second.
That left him 12th, which became a lowly 16th as others improved.
He jumped back to seventh when he came back out for another run, only to be pushed down to 13th by the flag.
Oliver Rowland's session followed a similar pattern and he ended up 15th.
|1||Antonio Giovinazzi||Prema Racing||1m56.607s||-|
|2||Pierre Gasly||Prema Racing||1m56.768s||0.161s|
|4||Norman Nato||Racing Engineering||1m57.211s||0.604s|
|5||Jordan King||Racing Engineering||1m57.411s||0.804s|
|7||Raffaele Marciello||RUSSIAN TIME||1m57.512s||0.905s|
|9||Nobuharu Matsushita||ART Grand Prix||1m57.665s||1.058s|
|12||Artem Markelov||RUSSIAN TIME||1m57.906s||1.299s|
|13||Sergey Sirotkin||ART Grand Prix||1m57.927s||1.320s|
|15||Oliver Rowland||MP Motorsport||1m57.987s||1.380s|
|17||Sean Gelael||Pertamina Campos Racing||1m58.252s||1.645s|
|18||Daniel de Jong||MP Motorsport||1m58.342s||1.735s|
|19||Mitch Evans||Pertamina Campos Racing||1m58.386s||1.779s|
|20||Jimmy Eriksson||Arden International||1m58.674s||2.067s|
|21||Nabil Jeffri||Arden International||1m59.292s||2.685s|
|22||Philo Paz Armand||Trident||1m59.577s||2.970s|