Cadillac Racing’s Pipo Derani was leading at the start of the ninth hour but soon pitted and relinquished the reins of the No. 31 Cadillac V-Series.R to team-mate Aitken.
As a result, Nick Tandy temporarily took the lead in the No. 6 Porsche Penske Motorsports entry before making way to team-mate Felipe Nasr in the No. 7 sister car. Meanwhile, Aitken ran third in the machine prepared by Action Express Racing.
Roughly halfway through the ninth hour, Jenson Button (Wayne Taylor Racing with Andretti) collided with the No. 4 Chevrolet Corvette GT3.R, which was running second in GTD Pro at the time, at Turn 3. The contact sent Button’s No. 10 Acura ARX-06 into a spin temporarily before gathering it back up and continuing.
Mathieu Jaminet took over from Tandy at the top of the 10th hour, returning to the track fourth, with Philipp Eng (BMW M Team RLL) rising to third behind Nasr and Aitken.
The No. 10 Wayne Taylor Racing with Andretti Acura, which suffered a power issue earlier, returned to the action halfway through hour 10, albeit 89 laps down.
Pitstops began again 15 minutes later, beginning with Jaminet and Nick Yelloly (BMW M Team RLL) pitting from third and fourth, respectively.
Ten minutes later Nasr and Aitken also came in for service, which included Dane Cameron taking over for Nasr. Even with the driver change, Cameron and PPM remained out front by 11 seconds. However, that margin soon shrank to 2.9s after catching traffic.
Then, in the early part of hour 11, Aitken lunged under Cameron into Turn 1, and used a Turner Motorsports BMW M4 GT3 as a pick to complete the pass for the lead. A ninth caution came out with 38 minutes remaining in hour 11 for debris at Turn 5.
Aitken stayed out but Jaminet and Cameron were brought into the pits for service, elevating both BMW M Team RLL entries to second and third, respectively. Laurens Vanthoor was changed out for Jaminet, while Cameron remained in and returned to the track in fourth.
Additionally, the No. 40 Wayne Taylor Racing Acura was called in as the crew swapped out for a new nose on the car, with Louis Deletraz also behind the wheel.
Aitken led the restart ahead of the BMW duo, which were quickly overtaken by Vanthoor.
Moments later, the No. 40 Acura ARX-06 was hit with an apparent power issue, much like the sister car earlier, and pulled off track and brought out the 10th caution of the event. Unlike the sister car, though, Deletraz was able to get refired and return to the action.
Aitken made a clean restart and held a 3s lead on Vanthoor at the midway stage.
Inter Europol/PR1 Mathiasen surges late to LMP2 lead
Pato O’Ward began the ninth hour with a 12s lead in the No. 2 United Autosports ORECA LMP2 07 over the Riley entry driven by Josh Burdon.
Through the cycle of pitstops and outright pace, O’Ward was able to build a 36s advantage over Burdon, who eventually handed over to Felipe Massa.
Halfway through hour 10, O’Ward widened the gap to 51s before Ben Keating took over and cycled back and eventually built up a lead of 38s lead over super sub Pietro Fittipaldi in the Inter Europol by PR1 Mathiasen Motorsports entry.
The ninth caution tightened the field back up, with Keating out front ahead of Tom Dillmann, who took over for Fittipaldi, and Massa.
Dillmann was able to take advantage on the restart and propel himself into the lead, with Massa following as Keating dropped to third.
On the restart after Acura’s issue, Dillmnan retained the lead but Connor Zilisch (Era Motorsport) rose to second, with Massa in third. Keating fell to fifth.
Risi establishes pace in GTD
The start of the ninth hour featured a welcome fight between the No. 64 Ford Mustang GT3 of Christopher Mies and No. 4 Corvette of Nicky Catsburg.
It was short-lived, though, as the biggest battle for the class lead came between AO Racing’s Laurin Heinrich in the No. 77 Porsche 911 GT3-R and Le Mans winner James Calado in the No. 62 Ferrari 296 GT3 for Risi Competizioni.
The two traded the top spot and ran inches from each other throughout the 12-turn, 3.56-mile road course before Calado established his presence out front.
Meanwhile, Heinrich pitted from second with 15 minutes left in hour 10, dropping to fifth and promoting Alexander Sims in the No. 3 Chevrolet Corvette GT3.R to second, 11s back.
Alessandro Pier Guidi took over from Calado and kept the squad out front, ahead of Sims.