Ferrari driver Pierre Kaffer edged BMW's Bill Auberlen in a closely fought qualifying for the GTLM-led United SportsCar round at Virginia International Raceway.
With the VIR event not featuring the USC's usual flagship Prototype class, the GTLM and GTD divisions have centre stage for a rare standalone race.
Auberlen was quickest at the beginning of the 15-minute session in the Rahal Letterman Lanigan-run BMW Z4, but great pace from Bryan Sellers then bumped the Falken Porsche 911 up to first, 0.4 seconds ahead.
Auberlen and Sellers continued to jockey for the quickest time, but it was close across the whole field as the top eight were soon all within 0.6s.
Kaffer snatched a time 0.256s quicker than Auberlen in the closing minutes in his Risi Ferrari 458 to take pole for himself and co-driver Giancarlo Fisichella, while Marc Goossens came from seemingly nowhere to quietly qualify third in the lead SRT Dodge Viper.
Muller was quick enough for fourth in the second BMW, having briefly been second, while SRT man Jonathan Bomarito was pleased to set a time 0.009s ahead of championship leader Antonio Garcia. Only eight points separate the Corvette and Viper crews in the drivers' standings.
For Garcia to even make it into qualifying was a remarkable achievement by Corvette. His co-driver Jan Magnussen was involved in a heavy practice crash when both he and Porsche driver Richard Lietz went off at the first corner in quick succession on fluid dropped by another car.
The Corvette slammed into the side of the Porsche. Lietz was transported to a local hospital for evaluation, with a USC statement describing him as awake and alert.
Magnussen was checked in the track's medical centre and will be examined again on Sunday morning before getting clearance to race.
Early pole contender Sellers finished a disappointing seventh after he looked to have the pace to challenge for pole, with Michael Christensen and Tommy Milner completing the GTLM runners.
In the GTD class, James Davison qualified on pole in the TRG Aston Martin, 0.297s ahead of second quickest Leh Keen in the Alex Job Porsche 911.
Championship leader Townsend Bell could only manage 14th quickest, 1.3s behind Davison, after a shunt in practice caused the AIM Ferrari to join the GTD qualifying session late.
The PC class has a pair of standalone races at VIR. Sean Rayhall took pole by a second in the 8Star entry he shares with Luis Diaz. The first race takes place on Saturday afternoon.
Leading qualifying positions:
Pos Cl Drivers Team/Car Time Gap
1. GTLM Fisichella/Kaffer Risi Ferrari 1m43.797s
2. GTLM Auberlen/Priaulx RLL BMW 1m44.053s +0.256s
3. GTLM Farnbacher/Goossens SRT Viper 1m44.072s +0.275s
4. GTLM Muller/Edwards RLL BMW 1m44.076s +0.279s
5. GTLM Bomarito/Wittmer SRT Viper 1m44.096s +0.299s
6. GTLM Magnussen/Garcia Corvette 1m44.105s +0.308s
7. GTLM Henzler/Sellers Falken Porsche 1m44.322s +0.525s
8. GTLM Long/Christensen CORE Porsche 1m44.422s +0.625s
9. GTLM Gavin/Milner Corvette 1m44.812s +1.015s
10. GTD Carter/Davison TRG Aston Martin 1m47.660s +3.863s