Reigning world champion Francesco Bagnaia has finished the opening day of the Portimao test on top of the timesheets by 0.234s over fellow Ducati rider Luca Marini.

Beaten to the top time by Marini (GP22) at Sepang, factory star Bagnaia (GP23) battled with the VR46 rider for supremacy throughout the day before settling the contest by being the only rider in the 1m 38s.

Home hero Miguel Oliveira (RNF Aprilia), Alex Marquez (Gresini Ducati) and Maverick Vinales (Aprilia) also joined the P1 battle in the final hours, before Raul Fernandez turned heads by edging out team-mate Oliveira for fifth.

The Malaysian test had ended with a Ducati-Aprilia top nine, a feat almost repeated at the start of Portimao, when Fabio Quartararo's Yamaha was the quickest of the Japanese machines in eighth (+0.843s), behind Marco Bezzecchi.

Alex Rins was the top Honda in eleventh with former Suzuki team-mate Joan Mir 14th for Repsol. Marc Marquez was just 19th and Takaaki Nakagami 23rd.

Enea Bastianini and Franco Morbidelli also had a tough opening day in 17th and 21st while late laps by KTM team-mates Brad Binder and Jack Miller pulled the pair up to 15th and 16th place. 

Fallers included Johann Zarco (twice), Fabio di Giannantonio (twice), Marc Marquez, Aleix Espargaro, Maverick Vinales, Nakagami and Mir.

di Giannantonio has gone to hospital for further checks after his crash at turn 7.

The technical novelties on show included some fork-mounted wings for Aprilia.

Is 2023 Make or BREAK for Yamaha? | Crash MotoGP Podcast EP.79

2023 Official Portimao MotoGP Test - Day 1 (FINAL)
1^3Francesco BagnaiaITADucati Lenovo (GP23)1m 38.771s77/78334.3
2˅1Luca MariniITAMooney VR46 Ducati (GP22)+0.234s58/65340.6
3˅1Maverick ViñalesSPAAprilia Racing (RS-GP23)+0.254s71/88334.3
4˅1Alex MarquezSPAGresini Ducati (GP22)+0.565s56/65337.5
5^9Raul FernandezSPARNF Aprilia (RS-GP22)+0.689s62/64335.4
6˅1Miguel OliveiraPORRNF Aprilia (RS-GP22)+0.695s59/75337.5
7˅1Marco BezzecchiITAMooney VR46 Ducati (GP22)+0.837s62/76337.5
8^4Fabio QuartararoFRAMonster Yamaha (YZR-M1)+0.843s88/90333.3
9˅2Fabio Di GiannantonioITAGresini Ducati (GP22)+0.870s32/50334.3
10˅2Jorge MartinSPAPramac Ducati (GP23)+0.872s38/63335.4
11˅2Alex RinsSPALCR Honda (RC213V)+0.875s66/77332.3
12˅2Aleix EspargaroSPAAprilia Racing (RS-GP23)+0.877s59/60338.5
13˅2Johann ZarcoFRAPramac Ducati (GP22)+0.945s44/57335.4
14^1Joan MirSPARepsol Honda (RC213V)+1.005s74/74329.2
15^5Brad BinderRSARed Bull KTM (RC16)+1.152s58/69335.4
16^5Jack MillerAUSRed Bull KTM (RC16)+1.216s57/58331.2
17˅4Enea BastianiniITADucati Lenovo (GP23)+1.238s27/52336.4
18˅2Stefan BradlGERHonda Test Rider (RC213V)+1.391s58/72331.2
19˅2Marc MarquezSPARepsol Honda (RC213V)+1.399s35/78336.4
20˅2Michele PirroITADucati Test Rider (GP23)+1.565s45/70333.3
21˅2Franco MorbidelliITAMonster Yamaha (YZR-M1)+1.643s75/95330.2
22=Pol EspargaroSPATech3 GASGAS (RC16)+1.736s58/64333.3
23^1Takaaki NakagamiJPNLCR Honda (RC213V)+1.871s68/74328.2
24˅1Augusto FernandezSPATech3 GASGAS (RC16)*+2.000s63/72330.2

^X Rider is X positions higher than previous hour.
= Rider is same position as previous hour.
˅X Rider is X positions lower than previous hour.

Official Portimao MotoGP records:
Best lap:
Francesco Bagnaia ITA Ducati 1m 38.725s (2021)
Fastest race lap:
Fabio Quartararo FRA Yamaha 1m 39.435s (2022)

The 2023 MotoGP grid has its last chance for pre-season preparations with a two-day official test at Portimao this weekend, the same circuit where the season-opener will take place on March 24-25.

VR46 Ducati’s Luca Marini has set the fastest lap time at both previous winter outings, at Valencia in November and then a three-day test at Sepang in February.

While Marini is using a year-old Ducati, Portimao will be the last chance for factory teams to pick the aerodynamic and, most importantly, engine with which they will start the 2023 racing season.

Once chosen, the engine design cannot be changed until the end of the world championship, while aero can be updated just once.

Testing takes place at Portimao from 9:30-17:30 on Saturday and Sunday, followed by practice starts.

What happened at the Sepang test?

Ducati and Aprilia riders filled the top nine positions on the Sepang timesheets, with Marc Marquez and Honda best of the rest in tenth.

While Ducati and Aprilia appeared to have made light modifications to their proven packages, Marquez whittled down four different Hondas to one preferred machine, but warned it was not good enough to win the title and more was needed for Portimao.

After a scare at Valencia, Yamaha riders Fabio Quartararo and Franco Morbidelli were pleased with their more powerful 2023 engine, selecting the final version for the racing season.

But while pleased with their pace, the bike ‘didn’t work’ in qualifying spec, with low fuel and new tyres, leaving them 17th and 20th on the combined times. Solving the qualifying issue, as well as a final decision on aero and chassis parts, will be among Yamaha’s priorities in Portimao.

The GASGAS/KTMs struggled the most on paper with Pol Espargaro best of the RC16s in 13th place followed by Brad Binder in 14th, Jack Miller in 18th and rookie Augusto Fernandez in 22nd. But with plenty of parts available and more to come, will the Austrian factory put the pieces together at Portimao?