Brendon Hartley put Porsche on provisional pole for the Le Mans 24 Hours after the opening qualifying session was brought to a premature end due to a crash.
Kiwi Hartley, who is partnered in the #20 Porsche 919 Hybrid by Mark Webber and Timo Bernhard, lapped in 3m23.157s to head a one-two for the German manufacturer on its return to the top class of the French enduro after 15 years away.
The other Porsche 919, driven by Neel Jani ,set the pace once the first representative runs had been completed.
Although he was swiftly overhauled by Hartley and later suffered a hydraulics issue, a 3m23.928s was good enough to clinch second ahead of the two Toyotas.
Porsche LMP1 vice-president Fritz Enzinger told AUTOSPORT: "That was not bad for the first day; we don't know what the others were doing, but we are still very happy.
"The afternoon [practice session] was quite difficult for us, because we did not have the right set-up but the evening was good."
Toyota's #8 TS040 HYBRID had topped practice in the hands of Anthony Davidson, but the Briton - partnered by Nicolas Lapierre and Sebastien Buemi - ended up just over two seconds adrift of the lead Porsche, and a tenth clear of the sister car of Alexander Wurz, Stephane Sarrazin and Kazuki Nakajima.
Last year's winner Audi only had two cars taking part in the first part of qualifying after Loic Duval's huge crash in practice, and its pair of R18 e-tron quattros could only manage fifth and sixth fastest in the hands of Andre Lotterer and Filipe Albuquerque.
Both Toyota and Audi were expected to usurp the Porsches at the top of the times until, with just under an hour left to run, Fernando Rees crashed his GTE Pro Aston Martin Vantage at the Porsche Curves.
That, along with Sarrazin slowing to a halt at the Dunlop chicane due to an oil leak in the Toyota, brought out the red flags, and Rees' incident caused sufficient barrier damage for the session to be brought to a premature end with half an hour still left on the clock.
In LMP2, the #26 OAK Racing Morgan-Nissan took provisional pole with Oliver Pla outpacing Paul-Loup Chatin in the #36 Signatech Alpine ORECA-Nissan by more than half a second.
It was closer in GTE Pro, but AF Corse Ferrari 458 driver Gianmaria Bruni beat the lead AMR Vantage, driven by Stefan Mucke, into second place by 0.3s, with Frederic Makowiecki (Manthey Porsche 911 RSR) and Antonio Garcia (Corvette C7.R) ensuring the top four places were locked out by four different manufacturers.
Ferrari was also on top in GTE Am, where the #72 SMP 458 driven by Andrea Bertolini led the similar #61 AF car of Marco Cioci by less than 0.2s.
Six cars failed to set a time. In addition to the #1 Audi's absence, the Nissan ZEOD RC, #41 Greaves Zytek-Nissan, two Imsa Porsches and 8Star Ferrari all failed to complete a flying lap.
Pos Cl Drivers Team/Car Time 1. P1 Bernhard/Webber/Hartley Porsche 3m23.157s 2. P1 Dumas/Jani/Lieb Porsche 3m23.928s 3. P1 Wurz/Sarrazin/Nakajima Toyota 3m25.313s 4. P1 Davidson/Lapierre/Buemi Toyota 3m25.410s 5. P1 Fassler/Lotterer/Treluyer Audi 3m26.388s 6. P1 Albuquerque/Bonanomi/Jarvis Audi 3m26.445s 7. P1 Kraihamer/Belicchi/Leimer Rebellion-Toyota 3m33.117s 8. P1 Prost/Heidfeld/Beche Rebellion-Toyota 3m34.922s 9. P2 Rusinov/Pla/Canal OAK Morgan-Nissan 3m38.843s 10. P2 Chatin/Panciatici/Webb Signatech Alpine-Nissan 3m39.490s 11. P2 Howson/Bradley/Imperatori KCMG ORECA-Nissan 3m39.586s 12. P2 Brundle/Mardenborough/Shulzhitskiy OAK Ligier-Nissan 3m39.822s 13. P2 Frey/Mailleux/Lancaster Race Perf ORECA-Judd 3m39.993s 14. P2 Berthon/Gonzalez/Chandhok Murphy ORECA-Nissan 3m41.502s 15. P2 Kimber-Smith/McMurry/Dyson Greaves Zytek-Nissan 3m41.847s 16. P2 Thiriet/Badey/Gommendy TDS Ligier-Nissan 3m42.730s 17. P2 Cheng/Tung/Fong OAK Ligier-HPD 3m42.988s 18. P2 Rast/Charouz/Capillaire Loeb ORECA-Nissan 3m43.507s 19. P2 Zlobin/Salo/Ladygin SMP ORECA-Nissan 3m43.618s 20. P2 Dolan/Tincknell/Gene Jota Zytek-Nissan 3m45.928s 21. P2 Klien/Hirsch/Brandela Morand Morgan-Judd 3m46.018s 22. P2 Ladygin/Minassian/Mediani SMP ORECA-Nissan 3m46.940s 23. P2 Schell/Leutwiller/Roussel Pegasus Morgan-Nissan 3m49.046s 24. P2 Ragues/Taylor/Ihara Larbre Morgan-Judd 3m53.948s 25. GTE P Bruni/Vilander/Fisichella AF Ferrari 3m54.754s 26. GTE P Turner/Mucke/Senna Aston Martin 3m55.067s 27. GTE P Holzer/Makowiecki/Lietz Manthey Porsche 3m55.516s 28. GTE P Magnussen/Garcia/Taylor Corvette 3m56.443s 29. GTE P Pilet/Bergmeister/Tandy Manthey Porsche 3m56.584s 30. GTE A Bertolini/Shaitar/Basov SMP Ferrari 3m56.787s 31. GTE A Perez-Companc/Cioci/Venturi AF Ferrari 3m56.919s 32. GTE A Dempsey/Foster/Long Dempsey Porsche 3m57.004s 33. GTE P MacDowall/O'Young/Rees Aston Martin 3m57.258s 34. GTE P Griffin/Parente/Leo Ram Ferrari 3m57.793s 35. GTE P Rigon/Calado/Beretta AF Ferrari 3m58.330s 36. GTE A Ried/Bachler/Al Qubaisi Proton Porsche 3m59.291s 37. GTE A Perrodo/Collard/Palttala Prospeed Porsche 3m59.394s 38. GTE P Gavin/Milner/Westbrook Corvette 3m59.445s 39. GTE A Mowlem/Patterson/Hamilton Ram Ferrari 3m59.794s 40. GTE A Barthez/Pons/Ayari Sofrev Ferrari 3m59.837s 41. GTE A Dalla Lana/Lamy/Nygaard Aston Martin 4m00.017s 42. GTE A MacNeil/Curtis/Bleekemolen Prospeed Porsche 4m01.226s 43. GTE A Wyatt/Rugolo/Bird AF Ferrari 4m02.452s 44. GTE A Nakano/Ehret/Rich Taisan Ferrari 4m03.066s 45. GTE A Krohn/Jonsson/Collins Krohn Ferrari 4m03.789s 46. GTE A Al Faisal/Neiman/Pumpelly JMW Ferrari 4m05.046s 47. GTE A Poulsen/Hansson/Thiim Aston Martin 4m06.464s 48. GTE A Mallegol/Bachelier/Blank AF Ferrari 4m11.533s 49. GTE A Mann/Case/Giammaria AF Ferrari 4m22.744s 50. C Ordonez/Reip/Motoyama Nissan ZEOD 51. P1 Di Grassi/Duval/Kristensen Audi 52. P2 Munemman/Latif/Winslow Greaves Zytek-Nissan 53. GTE A Maris/Merlin/Helary Imsa Porsche 54. GTE A Narac/Armindo/Hallyday Imsa Porsche 55. GTE A Montecalvo/Roda/Ruberti 8Star Ferrari