Despite a few drops of rain beforehand, the session started dry with the track soon inundated with cars as the skies were threatening with dark rain clouds.

Hartley was quickly into his groove, a 1m39.655s already under the 2015 pole time. His co-driver Mark Webber set a faster sector-three time later in the session but didn’t improve the time overall.

In the #2 car, Romain Dumas was warned about abusing track limits at Copse, recording the second-quickest time of 1m41.344s, some 1.6s off the Kiwi Hartley’s pace.

Then Marc Lieb suffered an off in the #2 car at Luffield, beaching the car in the gravel, which brought out a full course yellow.

In the battle for best of the rest, Loic Duval set the fastest first sector overall for Audi, on his way to a 1m41.454s, 1.799s off the pace – but only a tenth off the #2 Porsche.

That lap pushed back the Toyota of Kamui Kobayashi to fourth on 1m41.915s.

A rain shower five minutes before the end curtailed the quick times, with the Audi-Toyota symmetry repeated in positions five and six by the sister #7 Audi and #5 Toyota.

Rebellion led the way in the non-hybrid subclass over the ByKolles CLM.

Multi-team duel in LMP2

In LMP2, Pipo Dirani set the early pace for ESM on a 1m50.194s, already quicker than the class’s fastest morning time on his first run.

Gustavo Menezes took the top spot from him with a lap of 1m49.757s in the Signatech Alpine, but a flurry of late times in the final 30 minutes changed everything.

After ex-F1 racer Roberto Merhi went P2 with 1m49.994s for sportscar newcomers Manor, James Jakes then hit the front with a 1m49.696s in the sister car.

But Strakka Racing had the last laugh, as Jonny Kane set 1m49.632s to top the class in his Nissan-powered Gibson.

Ferrari rules the roost in GTE Pro

In GTE Pro, there was battle royal between the two AF Corse Ferrari 488s of Davide Rigon/Sam Bird and Gianmaria Bruni/James Calado.

Rigon set the ball rolling with a time of 2m01.917s, which was then topped by Bruni on 2m01.494s despite a warning for track limits.

Rigon closed the gap with 2m01.569s, and then took P1 on 2m01.069s.

Calado fought back with a 2m00.107s – almost a second clear of the sister car, before Rigon improved to a 2m00.313s, two tenths off, with Bird trimming off a few fractions on a 2m00.306s.

In GTE Am, the Gulf Racing Porsche led the way – although it suffered an off late in the session.

Pos	Driver	Car	Time	Gap
1	Mark Webber  Brendon Hartley  Timo Bernhard	Porsche 919 Hybrid '16	1:39.655	1:39.655
2	Marc Lieb  Romain Dumas  Neel Jani	Porsche 919 Hybrid '16	1:41.344	+1.689
3	Loic Duval  Oliver Jarvis  Lucas di Grassi	Audi R18 E-Tron Quattro '16	1:41.454	+1.799
4	Kamui Kobayashi  Mike Conway  Stéphane Sarrazin	Toyota TS050 HYBRID	1:41.523	+1.868
5	Andre Lotterer  Benoit Tréluyer  Marcel Fassler	Audi R18 E-Tron Quattro '16	1:41.678	+2.023
6	Anthony Davidson  Kazuki Nakajima  Sébastien Buemi	Toyota TS050 HYBRID	1:42.963	+3.308
7	Alexandre Imperatori  Mathéo Tuscher   Dominik Kraihamer	Rebellion R-One	1:46.428	+6.773
8	Nelson Piquet Jr.  Nick Heidfeld  Nicolas Prost	Rebellion R-One	1:47.685	+8.030
9	James Rossiter  Oliver Webb  Simon Trummer	CLM P1/01	1:48.590	+8.935
10	Jonny Kane  Nick Leventis  Danny Watts	Gibson 015S	1:49.632	+9.977
11	Tor Graves  Will Stevens  James Jakes	ORECA 05	1:49.696	+10.041
12	Nicolas Lapierre  Gustavo Menezes  Stéphane Richelmi	Alpine A460	1:49.757	+10.102
13	Roberto Merhi  Matt Rao   Richard Bradley	ORECA 05	1:49.994	+10.339
14	Ryan Dalziel  Pipo Derani  Chris Cumming	Ligier JS P2	1:50.026	+10.371
15	Roman Rusinov  René Rast  Nathanael Berthon	ORECA 05	1:50.268	+10.613
16	Ricardo Gonzalez  Filipe Albuquerque  Bruno Senna	Ligier JS P2	1:50.712	+11.057
17	Vitaly Petrov  Kirill Ladygin  Viktor Shaytar	BR Engineering BR01	1:51.946	+12.291
18	Scott Sharp  Ed Brown  Johannes van Overbeek	Ligier JS P2	1:52.082	+12.427
19	Nelson Panciatici  Ho-Pin Tung  David Cheng	Alpine A460	1:52.305	+12.650
20	Nicolas Minassian  Maurizio Mediani	BR Engineering BR01	1:52.680	+13.025
21	Gianmaria Bruni  James Calado	Ferrari 488 GTE	2:00.107	+20.452
22	Davide Rigon  Sam Bird	Ferrari 488 GTE	2:00.306	+20.651
23	Richard Lietz  Michael E. Christensen	Porsche 911 RSR	2:01.314	+21.659
24	Mike Wainwright   Adam Carroll  Ben Barker	Porsche 911 RSR	2:02.081	+22.426
25	Richie Stanaway  Fernando Rees	Aston Martin Vantage V8	2:02.525	+22.870
26	Billy Johnson  Olivier Pla  Stefan Mücke	Ford GT '16	2:02.775	+23.120
27	Pedro Lamy  Paul Dalla Lana  Mathias Lauda	Aston Martin Vantage V8	2:02.788	+23.133
28	Paolo Ruberti  Yutaka Yamagishi  Pierre Ragues	Chevrolet Corvette C7 GT3	2:02.911	+23.256
29	Khaled Al Qubaisi  David Heinemeier Hansson Klaus Bachler	Porsche 911 RSR	2:03.005	+23.350
30	Andy Priaulx  Marino Franchitti  Harry Tincknell	Ford GT '16	2:03.075	+23.420
31	Emmanuel Collard  Rui Aguas  François Perrodo	Ferrari F458 Italia	2:03.229	+23.574
32	Nicki Thiim  Marco Sørensen   Darren Turner	Aston Martin Vantage V8	2:03.253	+23.598
33	Christian Ried  Joël Camathias   Wolf Henzler	Porsche 911 RSR	2:03.392	+23.737