Tandy (Porsche Penske Motorsport 963) passed Cadillac’s Jack Aitken inside the final dozen minutes of the 2h40m event that was run for GTP and GTD machinery only.

The win was Roger Penske’s 100^th victory in sportscar competition.

Sebastien Bourdais, having whirled the Chip Ganassi-run Cadillac V-Series.R to a new track record in qualifying, led the field to green from Pipo Derani’s Action Express-run variant, who challenged at the outside of the Andretti Hairpin but couldn’t fashion an opening.

Bourdais came close to going off at the Corkscrew on the opening lap but clung on to his lead. Derani then had a scare inside the first 15 minutes when he clipped Mike Skeen’s GTD Mercedes at Turn 3. Derani pitted inside the first half an hour for two tires only, reporting that he was not happy with his car’s balance.

Behind Derani, Philipp Eng’s Rahal Letterman Lanigan Racing-run BMW M Hybrid V8 held third, ahead of the factory 963s of Jaminet and Dane Cameron and the Wayne Taylor Racing with Andretti Acura ARX-06s of Ricky Taylor and Louis Deletraz. After 30 minutes, Cameron got jammed up in GTD traffic at the Corkscrew, which allowed both Acuras to jump ahead of him.

Both Acuras quickly came under IMSA’s scrutiny: Taylor was forced to pit early to ‘address tire operational requirements’ and got lapped, while Deletraz received a warning for failing to adhere to powertrain parameters.

The race’s only full-course caution flew after 50 minutes for debris from the rear corner of the #7 Porsche, which eradicated Bourdais’ big lead. All the leaders pitted but Derani, after his early stop, was able to hand the #31 Cadillac over to Jack Aitken in just 15s as the car didn’t need as much fuel as its rivals.

Nick Tandy took over the #6 Porsche from Jaminet and restarted the race briefly in the lead from Aitken, who didn’t follow IMSA’s instructions when the class split occurred, and Tandy passed him (legally) under the yellow.

But, just after the green flag flew, Tandy locked up and ran wide at the Andretti Hairpin, gifting P1 back to Aitken on the run through Turn 2. Bourdais handed off to Renger van der Zande, slumping from first to third as it took a full energy load, with Jordan Taylor in for Deletraz in fourth.

Van der Zande muscled past Tandy at the Corkscrew just before half distance to grab second. Felipe Nasr, in the repaired #7 Porsche, also made a forceful move past Jesse Krohn (in the #24 BMW for Eng) to snatch fifth and soon acquired fourth from Jordan Taylor.

Tandy lost a heap of time when he ran wide avoiding a GTD Lamborghini in the Corkscrew, while Krohn suffered an off on the exit of Turn 3 and picked up a sponsor banner on the front of his car, and he tumbled to the tail of the GTP pack.

Aitken pitted from the final time with just under an hour to go, again benefiting from a shorter fill due to its three-stop strategy. Although he pitted later, van der Zande needed a longer stop get to the end and rejoined 5s in arrears. CGR also opted for no fresh tires, compared to Aitken’s two-tire call.

Tandy ran long to lead for a few laps and pitted with 46 minutes to go, also staying on his old rubber, splitting the Cadillacs as he rejoined in second. Aitken’s lead was carved into by Tandy in traffic, the pair even touching as Tandy lunged him at Turn 3 inside the final 30 minutes.

Aitken was clearly faster in clear air, but Tandy’s doggedness in traffic always gave him a chance to pounce.

With 12 minutes to go, Aitken got boxed in at Turn 4 behind two GTD cars, as a Corvette tried to pass a Porsche, and ran wide onto the dirt. Tandy lunged to the inside to grab the victory by almost 6s.

Nasr passed van der Zande, who struggled to repeat the car’s earlier pace, for third in the closing stages. Taylor also bullied his way past on the run to Turn 1 after they earlier clashed at the Corkscrew.

The BMW challenge flopped, as Connor De Phillippi #25 BMW M Hybrid V8 slumped to eighth from fifth on the opening lap and suffered an issue with its left-rear corner in the first pitstop. Team-mate Nick Yelloly then suffered a spin, but he battled back to seventh.

AO Racing, Porsche 911 GT3 R (992), GTD PRO: Laurin Heinrich, Seb Priaulx

Photo by: Jake Galstad / Motorsport Images

Porsche beats McLaren and Corvette in GTD

In GTD Pro, Chevrolet led after sweeping to a front row lock out in qualifying, with Nicky Catsburg in the #4 Corvette Z06 GT3.R leading team-mate Antonio Garcia (#3).

The first caution fell very kindly for the Pfaff Motorsports McLaren 720S, as Marvin Kirchhofer handed over the McLaren MP4/4 tribute-liveried car to Oliver Jarvis just at the right time to lead the #4 ’Vette, in which Tommy Milner took over from Catsburg.

Laurin Heinrich, in the AO Racing Porsche 911 he shares with Seb Priaulx, pushed Milner back to third after the restart. Heinrich then passed the McLaren for the win with a bold move at Turn 6 just after half distance.

Danny Formal led the opening GTD pro-am class exchanges in pole-winning Wayne Taylor Racing with Andretti’s Lamborghini Huracan from Patrick Gallagher’s Turner Motorsport BMW M4.

But the Turner BMW hit the front after the full-course yellow, and Robby Foley (in for Gallagher) looked set for the category win until he turned in on Jordan Taylor’s Acura inside the final five minutes at Turn 4.

The off-track moment that ensued was enough for the #57 Winward Racing Mercedes of Russell Ward and Philip Ellis to jump ahead, with the #120 Wright Motorsports Porsche of Adam Adelson and Elliott Skeer finishing third, the latter getting away with a wild slide at Turn 6 late on.