Martí made his single-seater debut in January 2021, driving for Xcel Motorsport in the Formula 4 UAE Championship.[6] He won a single race at the Yas Marina Circuit and came 7th in the standings, 184 points behind champion Enzo Trulli.[7] For the main season, he competed in Spanish F4 with Campos Racing, as the Valencian team made its debut in the championship.[8] He won two races at MotorLand Aragón and held a season-long fight for runner-up spot with teammate Sebastian Øgaard, ultimately finishing 3rd behind eventual champion Dilano van 't Hoff and Øgaard.[9]
Formula Regional
2022
Martí started 2022 racing in the rebranded Formula Regional Asian Championship for Irish-Filipino team Pinnacle Motorsport, alongside Formula 4 rival Van 't Hoff.[10][11] He got five podiums and 158 points from 15 races to claim second place in the overall standings, while also winning the rookie cup.[12]
After testing for the team in 2021 post-season, Martí made the step up to the FIA Formula 3 Championship in 2022 with Campos Racing.[14][15] Martí had a disappointing season, but in Imola during the feature race, he made a strategy gamble to stay on the wets on a drying track, and led the race for a number of laps before pitting for slicks. He finished the race in 15th. He scored his first points finish in the final round at Monza in the Sprint Race, where he finished 9th. He ended the season 26th in the standings with 2 points, ahead of teammate Hunter Yeany but far from other teammate and fellow countryman David Vidales. At the end of the season, Martí took part in the post-season test, remaining with Campos.[16]
2023
Martí continued with Campos Racing for the 2023 Formula 3 season.[17] He would finish fifth in the Drivers' Championship, taking two sprint race wins in Bahrain and Monaco, as well as a feature race win in his home GP in Spain.
Martí also competed in the Macau Grand Prix with Campos.[18] He ended his debut Macau race in fifth position, the highest Campos driver.[19]
Martí made his sportscar and prototype debut at the 2022 Historic Zandvoort Grand Prix competing in the Masters Endurance Legends, organised by Masters Historic Racing, in a Duqueine-run Norma M30. He won both races in his G2/P3 class and finished on the overall podium against higher class machinery in race 1.[22]