Black Falcon set the pace in the opening day of the Blancpain GT Series pre-season test, with Maro Engel going quickest by almost half a second on Wednesday.
The reigning Endurance Cup champion posted a best time of 1:52.856 in his Mercedes-AMG GT3 during the afternoon session.
Second fastest in the afternoon session was Team Parker Racing with its Bentley Continental GT3 driven by Seb Morris who lapped Circuit Paul Ricard 0.478 seconds slower than Engel.
However, the best time from the morning session was quicker than the Bentley, with Bertrand Baguette posting a 1:53.132 in the Honda NSX GT3.
Mercedes appeared to have a slight advantage over the course of the day, with the German manufacturer populating positions two through four in the morning session, and six of the top ten places in the afternoon.
On-track action gets back underway on Thursday with a further seven hours of running beginning at 9 p.m. local time.