Both were in the early battle for the lead at Portimao until Marquez outbraked himself at Turn 3 on Lap 3.
“On 26 March 2023, 14:06:02 during the MotoGP Race of the GRANDE PREMIO TISSOT DE PORTUGAL at Turn 3 you were observed as being overly aggressive causing a crash involving rider #88,” read the stewards' Notification of Sanction, in part.
“This contravenes the specific instructions given to MotoGP competitors and teams, disrupting the session, and is considered irresponsible riding causing danger to other competitors.
“It is therefore an infringement of Article 1.21.2 of the FIM World Championship Grand Prix Regulations.”
Marquez's new team-mate, Joan Mir, had to serve a long lap penalty during that Grand Prix race after he crashed in the Sprint race in attempting to pass Fabio Quartararo, although the Yamaha was only forced wide in that incident.
Mir finished the Grand Prix race in 11th and is now 13th in the championship on five points, two spots and two points behind his team-mate.
The Argentina MotoGP round takes place this coming weekend (March 31-April 2, local time).