Championship contender Tom Dillmann claimed his fifth pole position of the season in a damp Formula V8 3.5 qualifying session at Barcelona's title-deciding meeting
Although no rain was falling at the Circuit de Catalunya, conditions demanded all competitors began the half-hour session on wet tyres.
Highlighting the lack of grip, Dillmann's AVF team-mate Alfonso Celis Jr brought out the red flags when he found the tyre wall on the exit of Turn 5 just six minutes into the session.
Conditions improved sufficiently for several drivers to opt for slicks as qualifying built to a climax.
Among them were the eventual top-three of Dillmann, SMP Racing's Matthieu Vaxiviere, and GP3 race winner Jack Aitken.
Frenchman Dillmann's pole time of 1m44.909s was just 0.025s quicker than compatriot Vaxiviere.
Arden's Aurelien Panis, who is one of seven drivers disputing the drivers' crown this weekend, moved into provisional pole with four minutes left on the clocks, before being demoted by team-mate Egor Orudzhev.
Championship leader Louis Deletraz then found a 0.7s improvement to jump into P1.
The Fortec racer kept faith in his wet tyres, but in the final seconds he was bumped down to an eventual fourth place starting position for this afternoon's race by the three slick-shod men.
In starting behind his two closest rivals in the standings, Deletraz's chance of sealing the drivers' crown in race one on Saturday has been reduced.
Four-time 2016 winner Orudzhev will head the third row, from Jerez victor Matevos Isaakyan.
After topping Friday's second practice session, Roy Nissany endured a tough session, ending the morning in 14th.
Nissany's Charouz-run Lotus team-mate, and fellow title outsider, Rene Binder took 12th, behind improving Australian rookie Thomas Randle at Comtec.
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