Friday’s FP1 in Portugal marked the first time in 265 days six-time world champion Marc Marquez started an official MotoGP session, having suffered a serious arm break in the 2020 season-opener at Jerez.
Overnight rain left the Algarve circuit damp in places, which meant lap times started at around 15 seconds slower than the benchmark laps from last year.
As conditions continued to improve, so did the session-best laps, with a number of riders taking turns leading the timesheets.
Yamaha’s Vinales took over from reigning world champion Joan Mir with 16 minutes to go with a 1m44.777s, which he improved on his following tour to a 1m44.334s.
Francesco Bagnaia moved his factory Ducati ahead of the Qatar GP race winner with a 1m44.239s moments later, before Vinales dipped under the 1m44s bracket with a 1m43.544s.
The timing screen continued to light up as the opening 45-minute session of the weekend drew to a close, the returning Marquez serving a brief stint at the top of the pile with a 1m43.544s.
The Honda rider remained fastest for all of 10 seconds, before Bagnaia blasted his effort away with a 1m42.934s.
Amidst the flurry of laps at the end of the session, Marquez looked set to steal all the headlines when he shot back to the top of the order with a 1m42.378s on his final effort.
But faster laps for both Suzuki’s Alex Rins and Vinales denied this, the Yamaha rider setting the pace at 1m42.127s to lead Rins by 0.151s.
Marquez held onto third, 0.251s off Vinales’ pace ahead of Honda teammate Pol Espargaro, while championship leader Johann Zarco was fifth on his Pramac Ducati.
Bagnaia was shuffled back to sixth at the end ahead of Fabio Quartararo on the sister works Yamaha and Jack Miller on second factory team Ducati – the Australian fresh from arm pump surgery last week.
Alex Marquez was ninth on the LCR Honda ahead of Tech 3 KTM’s Danilo Petrucci, who revealed on Thursday he suffered a dislocated shoulder last month in Qatar.
Valentino Rossi was 11th on the Petronas SRT Yamaha, while champion Mir was 13th ahead of the other SRT bike of Franco Morbidelli.
Last year’s Portugal race winner Miguel Oliveira made a low-key start to his home weekend in the iffy conditions down in 17th on the factory team KTM, while teammate Brad Binder rounded out the 22-strong field.