GOAT Racing's Felipe Fernández topped the first free practice session by over 1.1 seconds in his Honda Civic Type R FL5 TCR, leading title contender Franco Girolami's Monlau Motorsport CUPRA Leon VZ TCR.
Fernández's best lap was his penultimate timed lap, with a time of 2:29.544, while his last lap was also only one tenth of a second slower, showing he had consistently strong pace in the 30-minute session.
Girolami made a late improvement to go second quickest, deposing the Audi RS 3 LMS of Nicola Baldan.
Championship leader Aurélien Comte was fourth quickest, with Ignacio Montenegro the second best of the Hondas in fifth position.
Series newcomers Jimmy Clairet and Eric Gené were seventh and 13th quickest in their CUPRAs at the end of the 30-minute session.
The next practice session is scheduled for 09:00 CEST tomorrow morning.