Zanchi has competed in the FIM Motocross World Championship since making three wildcard appearances in the 2023 season.
Zanchi won the 65 class of the Italian Junior Motocross Championship in 2017, winning all but one race on the way to the title.
Staying with the MJC Yamaha team for 2022, Zanchi started the season by finishing second in the 125 class of the Italian International Motocross Championship.
This good form was carried through to the start of the 2022 European Motocross Championship, where he won the opening race.
Alongside this, he made three wildcard appearances in the MX2 class of the 2023 FIM Motocross World Championship.
Domestically, Zanchi competed in the Elite MX2 class of the Italian Prestige Motocross Championship, finishing fifth in the final standings with two race wins.
Zanchi was signed by the Honda's factory Team HRC squad for the MX2 class of the 2024 FIM Motocross World Championship.