Porsche topped the times in final free practice for Saturday's Spa round of the World Endurance Championship with Marc Lieb at the wheel of the #14 919 Hybrid.
The German ended the two-hour session held in dry conditions with a 1m59.887s lap, which put him seven tenths up on second-fastest Sebastien Buemi at the wheel of the best of the Le Mans-spec Toyota TS040 HYBRIDs.
Third fastest was the quickest of the Audi R18 e-tron quattros, Andre Lotterer ending up a further tenth back on a 2m00.738s
Stephane Sarrazin (Toyota), Lucas di Grassi (Audi) and Mark Webber (Porsche) filled out places four to six on the timesheets.
The additional Audi on the entry at Spa, which is running in low-downforce Le Mans configuration unlike its two sister cars, ended up seventh on 2m02.620s in the hands of Filipe Albuquerque.
Olivier Pla was fastest in the OAK Racing-run G-Drive Morgan-Nissan in the LMP2 division, his 2m08.673s bettering Kirill Ladygin's best in the SMP ORECA-Nissan 03 by four tenths.
Gianmaria Bruni held sway for Ferrari in GTE Pro with a 2m18.913s.
The time was only two tenths quicker than the GTE Am best set by Klaus Bachler in the Proton Competition Porsche 911 RSR and six tenths up on team-mate Davide Rigon in the second-place Pro entry.
Qualifying for the Spa 6 Hours starts at 7:20pm local time on Friday evening.
Pos Cl Drivers Team/Car Time Cl gap 1. P1 Dumas/Jani/Lieb Porsche 1m59.887s 2. P1 Davidson/Lapierre/Buemi Toyota 2m00.638s +0.751s 3. P1 Fassler/Lotterer/Treluyer Audi 2m00.638s +0.851s 4. P1 Wurz/Sarrazin/Nakajima Toyota 2m01.292s +1.405s 5. P1 Di Grassi/Duval/Kristensen Audi 2m01.454s +1.567s 6. P1 Bernhard/Webber/Hartley Porsche 2m01.620s +1.733s 7. P1 Albuquerque/Bonanomi Audi 2m02.347s +2.460s 8. P2 Rusinov/Pla/Canal OAK Morgan-Nissan 2m08.673s 9. P2 Ladygin/Shaitar/Ladygin SMP ORECA-Nissan 2m09.100s +0.427s 10. P2 Dolan/Tincknell/Gene Jota Zytek-Nissan 2m09.552s +0.879s GT pacesetters: 14. GTE P Bruni/Vilander AF Ferrari 2m18.913s 15. GTE A Ried/Bachler/Al Qubaisi Proton Porsche 2m19.151s