Porsche driver Neel Jani returned to the track for a second qualifying run to claim pole position together with Marc Lieb for the Austin round of the World Endurance Championship.
Jani had been only fourth and nearly two seconds off the pace after a problem with the energy-retrieval systems left him with no hybrid boost on his first timed lap in the #18 Porsche.
Marc Lieb vaulted the 919 Hybrid up to second behind the sister car with a 1m46.405s before Jani got back in to set a 1m46.018s on old tyres to grab the extra point for pole position.
Jani and Lieb's laps combined to make an average of 1m46.211x, which was 0.164s ahead of that of team-mates Brendon Hartley and Timo Bernhard.
"I had zero hybrid boost, which gives you a brake problem, so I just had to finish the lap," said Jani.
"Audi was still close after Marc's lap, which is why I went out again.
"I never thought I could do a lap like that on old tyres."
Jani's problem on his first timed lap, following an early red flag, also cost the sister car time because he accidentally baulked Hartley.
Oliver Jarvis and Loic Duval were third fastest in the #8 Audi R18 e-tron quattro on a 1m47.538s average.
Audi, unlike Porsche, didn't use a second set of fresh tyres on either of its two cars.
Andre Lotterer had been quicker than Jarvis after the first runs, but team-mate Benoit Treluyer dropped to fourth, admitting that he "was not ready for qualifying" after getting limited running through free practice.
Sebastien Buemi and Kazuki Nakajima just edged out Toyota team-mates Mike Conway and Alex Wurz to claim fifth.
Matt Howson and Richard Bradley claimed LMP2 pole for the KCMG squad despite bringing out the red flags when the team's ORECA-Nissan 05 was hit by a fuel pressure problem leaving the pits at the start of the session.
The team managed to fix the problem after the car was returned to the pits through the infield, after which Howson set third best time in class.
Bradley's second lap was enough to give them pole with a 1m56.834s average.
That was three tenths up on the second-placed G-Drive Ligier-Nissan JSP2 qualified by Julien Canal and Sam Bird, who set the fastest single P2 lap of the session.
Aston Martin claimed pole in GTE Pro after Richie Stanaway set the fastest lap in class to propel the Vantage GTE in which team-mate Fernando Rees had initially been fourth fastest to the top of the order.
Stanaway set two laps in the 2m05s bracket on fresh rubber, his second time of 2m05.672s reducing the car's average to 2m05.872s.
Manthey Porsche duo Richard Lietz and Michael Christensen ended up second with a 2m06.134s average after using only one set of Michelins between them.
Class points leaders Gianmaria Bruni and Toni Vilander were only sixth in the their AF Corse Ferrari 458 Italia having complained of an understeering car.
Patrick Long and Patrick Dempsey claimed GTE Am honours for the Proton Porsche team.
|1||LMP1||R.Dumas, N.Jani, M.Lieb||Porsche Team||Porsche||1m46.211s||-|
|2||LMP1||T.Bernhard, M.Webber, B.Hartley||Porsche Team||Porsche||1m46.375s||0.164s|
|3||LMP1||L.di Grassi, L.Duval, O.Jarvis||Audi Sport Team Joest||Audi||1m47.538s||1.327s|
|4||LMP1||M.Fassler, A.Lotterer, B.Treluyer||Audi Sport Team Joest||Audi||1m47.898s||1.687s|
|5||LMP1||A.Davidson, S.Buemi, K.Nakajima||Toyota Racing||Toyota||1m48.990s||2.779s|
|6||LMP1||A.Wurz, S.Sarrazin, M.Conway||Toyota Racing||Toyota||1m49.176s||2.965s|
|7||LMP1||N.Prost, M.Beche, N.Heidfeld||Rebellion Racing||Rebellion/AER||1m53.950s||7.739s|
|8||LMP1||A.Imperatori, D.Kraihamer, D.Abt||Rebellion Racing||Rebellion/AER||1m54.506s||8.295s|
|9||LMP1||S.Trummer, P.Kaffer||Team ByKolles||CLM/AER||1m55.794s||9.583s|
|10||LMP2||R.Rusinov, J.Canal, S.Bird||G-Drive Racing||Ligier/Nissan||1m57.148s||-|
|11||LMP2||G.Yacaman, P.Derani, R.Gonzalez||G-Drive Racing||Ligier/Nissan||1m57.474s||-|
|12||LMP2||S.Sharp, R.Dalziel, D.H.Hansson||Extreme Speed Motorsports||Ligier/HPD||1m57.621s||-|
|13||LMP2||P.Ragues, O.Webb, A.Hamilton||Team SARD Morand||Morgan/SARD||1m58.109s||-|
|14||LMP2||N.Leventis, D.Watts, J.Kane||Strakka Racing||Gibson/Nissan||1m59.749s||-|
|15||LMP2||E.Brown, J.van Overbeek, J.Fogarty||Extreme Speed Motorsports||Ligier/HPD||2m01.480s||-|
|16||GTE Pro||F.Rees, A.MacDowall, R.Stanaway||Aston Martin Racing||Aston Martin||2m05.872s||-|
|17||GTE Pro||R.Lietz, M.Christensen||Porsche Team Manthey||Porsche||2m06.134s||-|
|18||GTE Pro||D.Turner, J.Adam||Aston Martin Racing||Aston Martin||2m06.272s||-|
|19||GTE Pro||M.Sorensen, C.Nygaard||Aston Martin Racing||Aston Martin||2m06.294s||-|
|20||GTE Pro||P.Pilet, F.Makowiecki||Porsche Team Manthey||Porsche||2m06.363s||-|
|21||GTE Pro||G.Bruni, T.Vilander||AF Corse||Ferrari||2m06.786s||-|
|22||GTE Pro||D.Rigon, J.Calado||AF Corse||Ferrari||2m06.975s||-|
|23||GTE Am||P.Dempsey, P.Long, M.Seefried||Dempsey Racing - Proton||Porsche||2m08.085s||-|
|24||GTE Am||F.Castellacci, B.Simonsen, S.Hall||Aston Martin Racing||Aston Martin||2m08.264s||-|
|25||GTE Am||F.Perrodo, E.Collard, R.Aguas||AF Corse||Ferrari||2m08.332s||-|
|26||GTE Am||P.D.Lana, P.Lamy, M.Lauda||Aston Martin Racing||Aston Martin||2m08.440s||-|
|27||GTE Am||V.Shaytar, A.Bertolini, A.Basov||SMP Racing||Ferrari||2m08.442s||-|
|28||GTE Am||G.Roda, P.Ruberti, K.Poulsen||Larbre Competition||Chevrolet||2m08.802s||-|
|29||LMP2||N.Panciatici, P-L.Chatin, V.Capillaire||Signatech Alpine||Alpine/Nissan||1m57.860s||-|
|30||LMP2||M.Howson, R.Bradley, N.Lapierre||KCMG||ORECA/Nissan||-||-|
|31||GTE Am||C.Ried, K.Al Qubaisi, E.Bamber||Abu Dhabi-Proton Racing||Porsche||-||-|