Vautier lapped the 3.56-mile course in 1min34.034sec, which eclipsed van der Zande in the similar #01 Cadillac of Chip Ganassi Racing by less than 0.1sec. The Dutchman was trying to respond when he went off at Turn 5 and went into the tires.
That brought out the red flag with under five minutes to go and so the session ended. Van der Zande lost his best laps and will start seventh.
Filipe Albuquerque will thus share the front row with Vautier, 0.122sec off the Caddy’s time in his Wayne Taylor Racing Acura ARX-05.
In third will be Alex Lynn in the second Ganassi Cadillac, alongside Tristan Nunez in Action Express Racing’s Whelen Engineering-backed entry.
AXR’s part-time car, the Ally Racing #48, was piloted very impressively to fifth by NASCAR legend and IndyCar sophomore Jimmie Johnson, less than 1sec off the ultimate pace and well ahead of Tom Blomqvist in the Meyer Shank Racing Acura.
Ben Keating and Steven Thomas, although 0.637sec apart, locked out the LMP2 front row for PR1/Mathiasen Motorsports, with Dennis Andersen claiming third for High Class Racing.
The two G-Drive by APR cars of Francois Heriau and John Falb were next up, ahead of Fritz van Eerd in the Racing Team Nederland car and John Farano of Tower Motorsports.
IMSA debutant Cameron Shields claimed pole in class for Muehlner Motorsports, the #26 Duqueine lapping in 1min42.182sec, which was 0.286sec quicker than Niko Pino in the Performance Tech Motorsports Ligier.
Jarett Andretti was third fastest, 1.6sec off the ultimate pace, but 0.016sec quicker than Ayrton Ori in the second Muehlner car. Jon Bennett was fifth in the CORE autosport Ligier ahead of Lance Willsey.
Alex Imperatori took pole for KCMG on the squad’s IMSA WeatherTech SportsCar Championship debut as times tumbled on a damp but drying track, his Porsche 911 GT3 R beating Porsche works driver Mathieu Jaminet in the Pfaff Porsche by just 0.063sec.
Andrea Caldarelli in TR3 Racing’s Lamborghini Huracan was third fastest in class, fifth of the GTs overall, ahead of Ross Gunn’s Aston Martin Vantage from the Heart of Racing team.
Davide Rigon will start fifth in class in the Risi Competizione Ferrari 488, just ahead of Vasser Sullivan Racing’s new boy in the Lexus RC F, Ben Barnicoat, and Maro Engel in the Proton Competition Mercedes-AMG GT3.
The sister Proton Mercedes piloted by Austin Cindric had a wayward moment that saw him damage his car against the GTD Carbahn with Peregrine Racing Lamborghini of Robert Megennis.
Fastest of the GTD non-Pro runners was the Sun Energy Mercedes of Kenny Habul, who did a remarkable job to be third fastest overall of the 29 GT cars that completed at least one flyer. He was less than two-tenths off Imperatori’s Lambo, and 0.151sec ahead of Russell Ward in the Winward Racing Mercedes.
John Miller got the McLaren 720S of Crucial Motorsports into third, while Michael de Quesada was fourth in the Alegra Motorsports Mercedes.
Fifth in class was Roberto Lacorte’s Ferrari 488 run by Cetilar Racing, with Frankie Montecalvo showing well as usual with the second VSR Lexus, ahead of the two GTD Pro Corvettes.
That isn’t the end of the IMSA WeatherTech SportsCar Championship action, as there will be a two-hour evening practice starting at 7.00pm local (Eastern) time.