The grid is set for Saturday's Six Hours of Circuit of The Americas, round five of the 2015 FIA World Endurance Championship, following qualifying on Friday evening at the 3.427-mile state-of-the-art Circuit of The Americas circuit near Austin, Texas.

LMP1

Brendon Hartley of the No. 17 Porsche led the prototype qualifying following his attempts. Andre Lotterer and Oliver Jarvis, at the controls of the No. 7 and the No. 8 Audis were second and third in front of Neel Jani who had failed in his attempts in the No. 18 Porsche.

Once Marc Lieb took the No. 18 Porsche from Jani, he was able to improve the average lap time to second place behind the No. 17, then driven by Timo Bernhard.

Meanwhile, Benoit Treluyer in the No. 7 Audi was unable to stay ahead of the No. 8, driven at that point by Loic Duval.

After Lieb had set the fastest time of the session, Jani piloted the No. 18 Porsche to an improved average lap time.

In the final moments of the qualifying, Jani improved his lap time enough for the No. 18 Porsche Team 919 Hybrid to claim the pole, 0.107 seconds ahead of the No. 17. Behind the two Porsches are the two Audi Sport Team Joest cars. The No. 8 Audi in third place lost 1.327 seconds to the polesitter and the fourth-placed No. 7 lost 1.687 seconds.

LMP2

In the secondary prototype category, the No. 47 Oreca 05-Nissan of KCMG set the fastest time to earn pole position for Saturday's six hour event at COTA.

The Ligier-Nissans of G-Drive Racing occupied the following two positions and will start P2 and P3 in-class on the grid. The second-placed No. 26 G-Drive Ligier was 0.314 seconds slower than the KCMG Oreca while the No. 28 G-Drive Ligier missed out on pole by 0.640 seconds.

GTE-Pro

Fernando Rees and Richie Stanaway qualified the No. 99 Aston Martin Vantage V8 on the GTE-Pro pole position.

The No. 91 Porsche was leading the qualifying after the attempts of Richard Lietz whereas the No. 99 Aston Martin was only fourth after Rees' attempts. Still, Michael Christensen couldn't keep the Porsche in the lead as Aston Martin driver Stanaway set the session's fastest lap in his attempts, carrying the No. 99's average lap time over that of the No. 91 Porsche by 0.262 seconds.

Aston Martin Racing's strong performance was accompanied with their No. 97 and No. 95 cars. The No. 97 was in fifth place after the attempts of Jonny Adam, yet Darren Turner's attempts lifted the car to third on the grid for Saturday's race. Marco Sorensen and Christoffer Nygaard set the fourth-quickest average lap and will start P4 on the grid.

Fifth-quickest was Porsche Team Manthey's No. 92 car. The No. 92 was in second after Frederic Makowiecki's attemps, yet Patrick Pilet couldn't match the pace of the Aston Martins.

GTE-Am

In GTE-Am, Patrick Long and Patrick Dempsey qualified the Dempsey - Proton Racing Porsche on class pole. Second-quickest were Benny Simonsen and Stuart Hall in the No. 96 Aston Martin.

The Six Hours of Circuit of The Americas will take start at 6:00 pm ET on Saturday. Follow @VAVELSportsCar on Twitter for continued coverage of the Six Hours of Circuit of The Americas weekend.

Kalle Tyynelä is a writer for the VAVEL USA Racing section. Follow him on Twitter at @FINdyCar.