Antonio Fuoco led the opening session at the Le Mans test day, while Toyota driver Mike Conway crashed in the closing minutes.
Fuoco reeled off a best lap of 3:30.686 aboard the No. 50 Ferrari 499P to go quickest overall.
The Italian driver outpaced the No. 94 Peugeot 9X8 of Gustavo Menezes by 0.660 seconds.
Yifei Ye came in third with a best lap of 3:31.477 aboard the No. 38 Hertz Team JOTA Porsche 963, making the privateer car the quickest Porsche entry in the first session.
The No. 51 Ferrari of James Calado and No. 7 Toyota GR010 Hybrid driven by Conway rounded out the top five.
Conway ended the first session in the barrier on the approach to Tertre Rouge, triggering a red flag with just a few minutes remaining. The car came to a rest on the grass with visible damage to the nose.
The No. 3 Cadillac V-Series.R finished the session in sixth in the hands of Renger van der Zande, ahead of the second Peugeot.
The French squad’s No. 93 machine also did not make it through the session without problems, as Paul di Resta triggered a red flag with 40 minutes remaining.
Di Resta brought the car to a halt on the exit of the first Mulsanne chicane with suspected hybrid issues.
The overall top ten was completed by Toyota’s Ryo Hirakawa, the No. 6 Porsche driven by Andre Lotterer and the No. 2 Cadillac in the hands of Earl Bamber.
Cool Racing set the quickest time in LMP2 as the No. 47 Oreca 07 Gibson recorded a best lap of 3:36.409, courtesy of Reshad de Gerus.
IDEC Sport’s Paul-Loup Chatin took second, ahead of the No. 31 Team WRT machine driven by Ferdinand Habsburg.
The No. 66 JMW Motorsport Ferrari 488 GTE Evo led GTE-Am with a best lap of 3:56.623.
The session was also interrupted by a 25-minute safety car period following a puncture for the No. 21 AF Corse Ferrari 488 GTE Evo of Julien Piguet.
Debris from the puncture on the exit of the first chicane, was used as an opportunity to practice the updated safety car procedure.
The second test day session starts at 3:30 p.m CEST (9:30 a.m. ET).
RESULTS: Test Session 1