Crutchlow in the mix
Cal Crutchlow (LCR Honda), meanwhile, was only a further 0.059 back in fifth to make it less than two tenths covering the top five.
It's a Ducati vs Honda duel for supremacy at the top: a factory rider settling in, last year's winner, the points leader seeking his first MotoGP podium at the venue, a three-time premier class Jerez winner and the 2019 polesitter.
If the initial Honda vs Ducati duel continues into qualifying, there was groundwork laid in FP1.
Honda took a 1-2 and Marquez sat behind Dovizioso for a couple of laps, and in FP2 the numbers 93 and 99 spent some time circulating in tandem as bad luck-struck Lorenzo got straight back into the mix near the front at one of his most successful venues and Marquez followed him around.
In terms of key drama on Day 1, there was a run on for Dovizioso, two crashes for Johann Zarco (Red Bull KTM Factory Racing) and a crash for Hafizh Syahrin (Red Bull KTM Tech 3).
Karel Abraham (Reale Avintia Racing) crashed and wildcard Bradley Smith (Aprilia Factory Racing) crashed in FP2, with the Red Flag briefly shown due to track conditions.
Tough for Rins
The biggest name not currently on course to move through to Q2 directly is Valentino Rossi.
It was also a tough day for the man who beat him to the top step at Americas GP, Alex Rins (Team Suzuki Ecstar), with the Spaniard down in P12. Rins hasn't finished outside the top six since Austria last season - and yes, he's finished every race.