Brendon Hartley topped the times in the #2 Porsche 919 Hybrid in the 90-minute session, which was interrupted by a short red-flag stoppage and light rain.

His 1m38.663s put him nearly a second ahead of teammate Andre Lotterer, who ended up on a 1m39.629s in the #1 machine.

Top Toyota driver Anthony Davidson was just behind, falling less than two tenths short with a 1m39.773s in the #8 TS050 Hybrid.

The sister #7 car was a further 1.8s in arrears in Kamui Kobayashi's hands.

The G-Drive Racing team led the way in LMP2 with a 1m47.188s from Ben Hanley, who is driving the team's #26 Oreca in place of Alex Lynn this weekend.

Rebellion took second in class thanks to a 1m47.410s from Mathias Beche in the #13 Oreca.

The top positions in GTE Pro category were shared by all four manufacturers.

Porsche was quickest with a 1m56.244s from Frederic Makowiecki, which put him almost exactly a tenth up on Aston Martin driver Nicki Thiim.

Ferrari took third in the with Alessandro Pier Guidi setting a 1m56.766s, while Stefan Mucke was fourth for Ford.

Miguel Molina was the quickest driver in GTE Am for the AF Corse-run Spirit of Race Ferrari team.

Practice results: