Marcus Wittmann put his BMW M4 on pole at Zolder for the opening race, pipping Rast to the post by just half a tenth.
The German set his best time on the first run, logging a 1:21.307, knocking Audi man Rast down to second.
The drivers waited until the last few minutes to make their second runs but traffic proved to be a hindrance, stopping most teams from improving on their earlier times.
Spengler took third ahead of rookie van der Linde with Frijns making it 3 BMWs in the top five.
At the bottom of the field, Rockenfeller radioed to his team with a clutch problem. Once he pitted, he was then reported to the stewards for spinning his wheels on the air jacks, ending a rough session in 16th.
Full results below: