The Marc VDS BMW team claimed top spot in qualifying on Thursday ahead of the Super Pole session that will determine the first 10 rows of the grid for this weekend's Spa 24 Hours.
Factory driver Dirk Werner set the pace in the first of two 75-minute sessions on Thursday evening aboard the BMW Z4 he shares with Lucas Luhr and Markus Paltalla.
Werner set a best time of 2m19.089s right at the beginning of the session, a time that was almost matched by Christopher Mies in the best of the WRT Audi R8 LMS ultras.
Mies's lap of 2m19.130s put him just four hundredths of a second behind the BMW driver.
The greatest Spa 24 Hours?
Werner, whose Marc VDS team is racing in the Blancpain Endurance Series for the first time this year, said: "It's difficult to come into a championship where you don't know the tyres.
"We made some changes over the day and we now know that we have figured up a good set-up, at least for one lap."
Kevin Estre was third fastest for the ART McLaren squad.
The Frenchman ended up a tenth and a half behind Mies on a 2m19.248s aboard his MP4-12C.
Alessandro Pierguidi ended up fourth and first in the Pro-Am class at the wheel of his AF Corse Ferrari 458 Italia.
Top Mercedes driver was Bernd Schneider, who was part of the winning line-up last year, in seventh place.
His best of 2m19.650s was only just over half a second behind Werner's mark.
The championship-leading Bentley Continental GT3 shared by Steven Kane, Guy Smith and Andy Meyrick just made it into Super Pole, which starts at 18:50pm local time on Friday.
Kane ended up on a 2m20.448s, but had been on a faster lap when red flags came out to stop the first session came out.
He subsequently went second quickest in the slower second night session.
The second ART McLaren did not take part in qualifying after Alvaro Parente crashed heaving during open practice at the second left-hander at Pouhon.