At Suzuki, meanwhile, work continued on the new engine. Mir had the upper hand on the time sheets in third after 56 laps, with team-mate Rins putting in 69 in fourth.
Test rider Sylvain Guintoli was also on track for the Hamamatsu factory, and he put 63 laps to pip his fellow test riders and end the day in 16th. It was not all engine for Suzuki, but that was the key focus.
Honda were the next factory up, with reigning champion Marc Marquez (Repsol Honda Team) in sixth despite a crash at Turn 13. It was a slow lowside but in the gravel trap he hit his shoulder, heading to the Medical Centre for a check up.
He had suffered a partially dislocated right shoulder - not the one on which he had surgery this time last year - and did get back out on track but said he slowed up slightly. He had three bikes in the garage. And where Marquez was focusing on 2020 comparisons, Cal Crutchlow (LCR Honda Castrol) was more on 2019 machinery as he was just 0.026 behind the Spaniard and put in 66 laps.
Rookie Alex Marquez (Repsol Honda Team), meanwhile, was out in HRC and Repsol colours, and he seemed to take a step forward.
The number 73 was 17th and did 70 laps, saying he found Jerez a bigger step on a MotoGP bike - but also an easier one.
KTM were the fourth fastest factory with Pol Espargaro (Red Bull KTM Factory Racing), the number 44 slotting in behind Marquez and Crutchlow on the time sheets. He did 56 laps and although he took a tumble was deemed okay.
Red Bull KTM Tech 3 rookie Iker Lecuona had a huge crash, but the rider did 38 laps. Test rider Dani Pedrosa was absent due to illness.