Two weeks on from a double disaster for Gresini Ducati at the Americas GP when both Alex and Marc Marquez suffered crashes, the brothers led the 45-minute FP1 at Jerez on Friday morning.
Eight-time world champion Marc Marquez led for much of the session, but ended up 0.507 seconds adrift of his team-mate Alex Marquez after he fitted fresh soft tyres to produce a 1m36.630s at the end of FP1.
Americas GP winner Maverick Vinales led an Aprilia 3-4 from Aleix Espargaro, while Franco Morbidelli was fifth on the leading factory-spec Ducati for Pramac.
Championship leader Jorge Martin was a low-key ninth on the sister Pramac Ducati, while reigning world champion Francesco Bagnaia was 12th.
Vinales picked up where he left off at the Circuit of the Americas by setting the early pace in FP1 at Jerez with a 1m39.113s inside the first five minutes of the session.
This was quickly beaten by Marc Marquez on a 1m38.784s, before Vinales fired in a 1m38.738s just seconds later.
Trackhouse Racing Aprilia’s Raul Fernandez was the next rider to move to the top of the order with a 1m38.637s with six minutes of the session gone.
Francesco Bagnaia, Ducati Team
Photo by: Gold and Goose / Motorsport Images
But he would find himself quickly deposed as Marc Marquez went on a run of session-best laps that began with a 1m37.768s and culminated in a 1m37.137s.
That stood as the benchmark until the final four minutes, when Alex Marquez began lighting up the timing screens on fresh soft rubber to take top spot away from his brother with a 1m36.630s.
With nobody else electing to run fresh soft rubber, Alex Marquez remained out of reach as the chequered flag brought FP1 to an end.
Marc Marquez held onto second by 0.084s from Vinales after a later surge from the factory Aprilia duo cemented them third and fourth.
Morbidelli completed the top five, 0.244s further adrift, as he made a strong start to the weekend at the venue he scored his last MotoGP podium in 2021 with Petronas SRT Yamaha.
Marco Bezzecchi was an encouraging sixth on the VR46 Ducati after his difficult start to 2024, while KTM wildcard Dani Pedrosa led the Austrian manufacturer’s contingent from Brad Binder.
Martin and Tech3’s Pedro Acosta completed the top 10, with Fabio Di Giannantonio (VR46) putting his year-old Ducati between Acosta and factory Ducati rider Bagnaia.
Fabio Quartararo, Yamaha Factory Racing
Photo by: Gold and Goose / Motorsport Images
Fabio Quartararo was the leading Yamaha in 14th behind the second factory Ducati of Enea Bastianini, who comes to Jerez second in the standings, while top Honda honours went to Johann Zarco in 19th.
However, the LCR rider did suffer a crash with 20 minutes of the session to go at Turn 8. Tech3’s Augusto Fernandez in 20th was the only other faller in FP1.
Aprilia wildcard Lorenzo Savadori was 23rd on the RS-GP lab bike, while Honda’s additional entry Stefan Bradl was a place behind on an RC213V with various revisions headlined by a radical rear wing.