There was an early return to pit lane for Alex Rins after the soon-to-be LCR Honda rider had part of his left fairing hanging off his GSX-RR machine.
The fairing came loose when Rins made a downshift along the back straight before heading back to his Suzuki garage.
With weather conditions overcast but humid, something that’s likely to change over the weekend, Miller, Quartararo and Marc Marquez were the riders showing early pace.
With 15 minutes gone of the extended FP1 session, Miller was the only rider able to break underneath the 1m 46s barrier. Miller was then knocked off the top spot when Quartararo set a time of 1:45.807s.
Still showing good pace aboard his Repsol Honda, Marquez then had a big moment on the approach to turn three as the rear of his bike snapped around under braking, leading to him running wide.
With just under half the session complete, the dreaded sight of rain flags were deployed by marshals trackside.
Luckily for the riders currently on track, the rain was very light which had little impact on the lap times being churned out.
One of the first riders to change to soft tires, Rins jumped to the top of the leaderboard with a time of 1:45.738s.
After making a relatively small improvement on the soft tires, Rins was quickly bumped down to second by Johann Zarco, who went four tenths quicker than the Suzuki man.
The hero of Honda’s stunning performance at the Suzuka 8 hours event, Tetsuta Nagashima caught trouble after getting beached in the gravel [sector three].
The Japanese rider was quickly assisted by marshals in order to remove his RC213V from the gravel.
As lap times continued to ramp up, Espargaro closed to within +0.013s of Zarco before Quartararo went quickest by nearly two tenths.
Despite losing time in sector four compared to his rivals, Quartararo was proving to be very strong in the first three.
Winner of the Aragon MotoGP, Enea Bastianini then bolted into action by going quickest with a first sub 1m 45s lap of the day.
Not to be outshone in what will be Suzuki’s final home race in MotoGP, Rins jumped back to the top of the timing sheets with a time of 1:44.961s.
With just ten minutes remaining, Rins then went even quicker on his next lap around.
As the final time attack runs began, Miller quickly became the rider to beat as he went three tenths clear.
Miller then set another brilliant lap despite being held up by Takuya Tsuda, who is replacing an injured Joan Mir this weekend, to go quicker once again.
Improvements from all three title contenders Bagnaia, Quartararo and Espargaro saw them slot in beind Miller, however, the same wasn’t true for Bastianini who crashed at turn five.
That was then followed by falls for Zarco at turn seven and RNF Yamaha rider Darryn Binder.