Whilst there was no change to the overall leader as the race completed its 21st hour, the #10 Acura still pacing the field, there was a drama behind for a previous race leader as the #31 Whelen/ Action Express Cadillac went behind the wall, the car stuck in third gear. That cost the team 20 minutes putting the car back in amongst the LMP2s. A Full Course Yellow soon after the car joined for debris saw the field compress once again, allowing the #55 Mazda back onto the lead lap a minute back from the leader, fifth in the order.
At the head of the pack when the race went green Kevin Magnussen took a look at taking the lead around Alex Rossi, made it briefly through the Bus Stop but lost speed going onto the banking and ceded the lead back. He tried again though and executed the perfect pass, took the lead but was promptly pitted for a pit stop infringement, dropping the #01 to fourth, 20 seconds ahead of the Mazda.
LMP2 saw a lead change as the #18 Era Oreca made its way by to led, Paul Loup Chatin building on fine work from Kyle Tilley.
The #8 Tower Motorsports car dropped to third behind the surviving #82 DragonSpeed car right until the end of the 21st hour when the #82 pitted with smoke from the rear, the car released after a slightly extended stop, now third with the #8 back up into second.
There was a further drama too in the 21st hour from the already heavily delayed #52 Oreca, behind the wall as the 22nd hour began.
GTLM saw the Corvettes still in charge, the #3 passed in the pits under the FCY by the Rise Ferrari but the #62 was ordered to give back the spot after a pit stop infringement.
Corvette chose to shuffle their pack with Jordan Taylor passing Nick Tandy for the lead and pulling away with the remainder of the time to the end of Hour 21 under green.
Much of the notable action came in GTD with a spirited lead battle between the #57 AMG and the #21 AF Corse Ferrari some wheel to wheel stuff dealing out the thrills before a clash into turn one, adjudged a racing incident by race control, that saw the Ferrari in the tyres with left rear damage and the AMG emerging relatively unscathed. That put the #21 out of it and off the lead lap, the #57 now in another AMG on AMG battle with the #75 SunEnergy1 car. One further retirement in the period came deep into the 21st hour as the drivetrain of the #9 Pfaff Porsche cried enough, Zach Robichon pulling off into retirement.
Top fives after 21 hours
#10 Wayne Taylor Racing Acura ARX-05c
#48 Ally Cadillac Racing Cadillac DPi-V.R.
#60 Meyer Shank Racing Acura ARX-05c
#01 Cadillac Chip Ganassi Racing Cadillac DPi-V.R.
#55 Mazda Racing RT-24P
#3 Corvette Racing C8.R
#4 Corvette Racing C8.R
#24 BMW M8 GTE
#62 Risi Competizione Ferrari 488 GTE
#25 BMW M8 GTE
#18 Era Motorsport ORECA 07
#82 DragonSpeed ORECA 07
#8 Tower Motorsports ORECA 07
#51 RWR/ Eurasia Ligier JS P217
#11 WIN Autosport ORECA 07
The #74 Riley-Robinson Ligier JS P320
The #33 Sean Creech Motorsports Ligier JS P320
The #6 Muehlner Motorsports Duqueine D08
The #91 Riley-Cox Ligier JS P320
The #54 CORE Autosport Ligier JS P320
#57 Winward Racing Mercedes AMG GT3
#75 SunEnergy1 Mercedes AMG GT3
#16 Wright Motorsports Porsche 911 GT3 R
#1 Paul Miller Racing Lamborghini Huracan GT3 Evo
#23 Heart of Racing Aston Martin Vantage GT3
#9 Pfaff Motorsport Porsche 911 GT3 R (drivetrain)
P43: #64 Team TGM/ Wright Porsche 911 GT3 R
P44: #7 Forty7 Motorsports Duqueine D08 (Oil pump)
P45: #111 GRT Grasser Racing Team Lamborghini Huracan GT3 Evo (Engine)
P46: #19 GRT Grasser Racing Team Lamborghini Huracan GT3 Evo (Engine)
P47: #29 Racing Team Nederland ORECA 07 (Gearbox)
P48: #20 High Class Racing ORECA 07 (Gearbox)
P49: #81 DragonSpeed ORECA 07 (Crash/Engine)