The major story of the first official test ahead of the 2024 season was Marc Marquez's debut on the Gresini Ducati.
It marked the first time in his MotoGP career that he took to the track on a bike that wasn't a Honda and generated a considerable amount of buzz on Tuesday morning as he prepared for his first run.
Taking to the circuit on his sponsor-less Ducati at 11:14am local time, about an hour and 15 minutes into the session, Marquez ended his first run third fastest.
With just over an hour and a half to go in the day, Marquez shot to the top of the order with a 1m29.460s before improving to a 1m29.424s.
His time at the top of the standings wouldn't last and he would finish up his day well before the 5pm chequered flag.
Ending the day fourth, Marquez was just 0.171s off the best pace set by Vinales, who put the 2024 RS-GP through its paces and led the day with a 1m29.253s.
Only six riders posted lap times inside the opening hour of running under cold and windy conditions, with Vinales fastest at the end of hour one on a 1m31.256s.
His session-best lap would come in the closing stages of his 86-lap day, Vinales ending up 0.028s clear of Binder.
The South African leapt up to the top two late on his 2024-spec KTM, with Binder and team-mate Jack Miller testing a new aerodynamic concept – among other things – disguised by a camo livery.
Marco Bezzecchi was third on his 2023-spec VR46 Ducati, edging ahead of Marc Marquez by 0.078s as Raul Fernandez tested for Aprilia despite RNF Racing's recent collapse.
Alex Marquez was sixth on the second Gresini Ducati as he got to grips with the power delivery of the 2023 Ducati, while Fabio Di Giannantonio was seventh on his VR46 debut.
Enea Bastianini led Miller on his factory Ducati, with Luca Marini 10th and 0.703s off the pace on his Honda debut.
World champion Francesco Bagnaia was 11th ahead of Fabio Quartararo on the updated 2024-spec prototype Yamaha, while Joan Mir was 13th.
Championship runner-up Jorge Martin crashed twice on Tuesday, his first coming on his first run of the 2024-spec Ducati.
The Pramac rider was 15th, 0.054s ahead of new Pramac team-mate Franco Morbidelli.
Johann Zarco was 17th after a crash on the LCR Honda, while MotoGP rookie Pedro Acosta was 1.2s off the pace in 18th after a tumble on his Tech3 GasGas.
Aleix Espargaro (Aprilia) ended his day after only 17 laps to return to Barcelona for treatment on the leg he fractured in Qatar two weeks ago and was 22nd.
Alex Rins was 19th on his Yamaha debut, 1.3s off the pace.
| Cla | Rider | Bike | Time | Gap | Laps |
| 1 | Maverick Vinales | Aprilia | 1'29.253 | 86 | |
| 2 | Brad Binder | KTM | 1'29.281 | 0.028 | 51 |
| 3 | Marco Bezzecchi | Ducati | 1'29.346 | 0.093 | 62 |
| 4 | Marc Marquez | Ducati | 1'29.424 | 0.171 | 49 |
| 5 | Raúl Fernandez | Aprilia | 1'29.516 | 0.263 | 64 |
| 6 | Alex Marquez | Ducati | 1'29.638 | 0.385 | 56 |
| 7 | F.Di Giannantonio | Ducati | 1'29.662 | 0.409 | 60 |
| 8 | Enea Bastianini | Ducati | 1'29.796 | 0.543 | 56 |
| 9 | Jack Miller | KTM | 1'29.901 | 0.648 | 62 |
| 10 | Luca Marini | Honda | 1'29.956 | 0.703 | 72 |
| 11 | F.Bagnaia | Ducati | 1'29.970 | 0.717 | 51 |
| 12 | Fabio Quartararo | Yamaha | 1'30.022 | 0.769 | 63 |
| 13 | Joan Mir | Honda | 1'30.051 | 0.798 | 69 |
| 14 | A.Fernandez | KTM | 1'30.077 | 0.824 | 72 |
| 15 | Jorge Martín | Ducati | 1'30.152 | 0.899 | 51 |
| 16 | F.Morbidelli | Ducati | 1'30.206 | 0.953 | 69 |
| 17 | Johann Zarco | Honda | 1'30.283 | 1.030 | 61 |
| 18 | Pedro Acosta | KTM | 1'30.476 | 1.223 | 70 |
| 19 | Alex Rins | Yamaha | 1'30.564 | 1.311 | 54 |
| 20 | Cal Crutchlow | Yamaha | 1'30.765 | 1.512 | 74 |
| 21 | Takaaki Nakagami | Honda | 1'30.976 | 1.723 | 63 |
| 22 | Aleix Espargaro | Aprilia | 1'32.312 | 3.059 | 17 |
| 23 | Lorenzo Savadori | Aprilia | 1'32.684 | 3.431 | 27 |
