Porsche claimed its fourth consecutive victory in the FIA World Endurance Championship at Austin, as Mark Webber, Brendon Hartley and Timo Bernhard extended their winning streak to three races.
The #1 Porsche 919 Hybrid crossed the line 23.6 seconds ahead of the #8 Audi R18 driven by Lucas di Grassi, Loic Duval and Oliver Jarvis, which had led early on but lost its lead through numerous problems.
Audi had the quickest car at the Circuit of the Americas, but its inability to match the reliability of the leading Porsche meant it missed out on another golden opportunity for top points.
The #8 car lost its lead under the first vestiges of darkness when Duval’s hybrid system gave up on him at turn one. That promoted the #7 Audi – shared by Andre Lotterer, Marcel Fassler and Benoit Treluyer – to the lead of the race, but a virtual safety car allowed Porsche to inherit the advantage.
Both Audis pitted under green flag conditions while the Porsche came in just after the full course yellow was called. As a result, the Porsche turned its temporary pit stop lead into a net lead by saving time through pitting when the other cars were circulating much slower around the 3.4 mile circuit.
From then on, Bernhard led the field with Treluyer chasing in second, but the Audi was dealt a severe blow to both its race and championship chances when the French driver went off at turn 18. A clip from the #66 GTE-class Ford was enough to send the Audi off into the SAFER barrier, prompting repairs that dropped it eight laps behind the overall pace.
That paved the way for Bernhard, who made no mistake of guiding his Porsche to another unexpected but deserved victory. Duval finished second, marginally ahead of the #6 Toyota which had entered the frame late on thanks to a strong double stint by Stephane Sarrazin.
Fourth place belonged to the championship-leading #2 Porsche which had a quiet race, ahead of the sister Toyota.
Rebellion Racing won the battle for LMP1 privateer honours, with Alexandre Imperatori, Matheo Tuscher and Dominik Kraihamer finishing seventh overall to beat the rival Bykolles Racing CLM.
In LMP2, Signatech Alpine extended its championship lead further with a dominant victory.
Nicolas Lapierre, Gustavo Menezes and Stephane Richelmi were left unchallenged after the third full course yellow, which saw Signatech come in during the slow period while its rivals had already pitted under green.
That opened up a one lap lead to the RGR Sport by Morand Ligier, with G-Drive Racing coming home third after Alex Brundle worked his way up from the back of the grid during his opening stint.
GTE-Pro honours went to Aston Martin Racing, as Nicki Thiim and Marco Sorensen claimed their first win as a pairing. It was also the first win for Sorensen in the World Endurance Championship, while Thiim celebrated his first visit to the top step of the podium since 2014.
The #95 Aston – which takes the championship lead after this weekend’s result – finished 11 seconds ahead of the Gianmaria Bruni/James Calado Ferrari 488 which despite getting close couldn’t apply sufficient pressure to alter the result.
The sister Ferrari finished third, with the #67 Ford GT coming fourth ahead of the #97 Aston which lost its points lead.
Aston Martin’s success continued in GTE-Am, with Paul Dalla Lana, Mathias Lauda and Pedro Lamy beating the KCMG Porsche 911 to the line by just over a minute.