The Japanese driver was installed at the wheel of the #8 Toyota GR010 Hybrid with around two hours left on the clock, taking over from Brendon Hartley, and was around 16 seconds in arrears of the Ferrari of Antonio Giovinazzi.
But just three laps into his stint, Hirakawa appeared to suffer a rear lock-up exiting Indianapolis, putting him in the barriers at Arnage and leaving the Toyota with rear-end damage.
Hirakawa managed to get back to the pits, where the Toyota crew replaced the front and rear decks without wheeling the #8 car into the garage - turning it around in just over two minutes.
Miraculously, it meant Hirakawa stayed on the lead lap, but a daunting three minutes, 20 seconds behind Giovinazzi heading into the final hour-and-a-half of the race.
The #2 Cadillac V-Series.R remained in third place, a lap down on the leading Ferrari with Richard Westbrook at the wheel.
