Lunetta began riding minibikes at the age of five and won various Italian and European pocketbike championships as a child. A formative influence on his career has been the late Marco Simoncelli: since his youth, Lunetta has raced under Simoncelli's iconic number 58 as a tribute to the Italian rider's legacy.
His structured development began in 2019 when he won the CIV PreMoto3 250 Championship. In 2020, at the age of fourteen, he entered the Red Bull MotoGP Rookies Cup and scored points on three occasions across ten race starts. A second Rookies Cup season in 2021 saw him finish thirteenth overall, supplemented by a sixteenth-place result in the FIM CEV Moto3 Junior World Championship.
By 2022 his results had sharpened considerably: he took one win and four podiums in his final Rookies Cup season and finished eleventh in the Junior GP. That year he also made his Moto3 World Championship debut as a replacement for injured Matteo Bertelle at the Dutch TT, finishing nineteenth.
In 2023, Lunetta remained outside the full-time Moto3 grid but made the most of his final junior season. He finished championship runner-up in the JuniorGP series behind Ángel Piqueras, a result that demonstrated consistent front-running pace at the highest junior level. He also made a second World Championship appearance, competing in the Moto3 Italian Grand Prix as a wildcard, further building his experience on the grand prix stage.
On 10 August 2023, it was announced that Lunetta would join the Moto3 World Championship full-time for 2024 with Sic58 Squadra Corse — a team whose very name commemorates Marco Simoncelli — alongside compatriot Filippo Farioli. The symmetry with his career-long tribute to Simoncelli made the placement particularly resonant.
Lunetta delivered a strong rookie season. He claimed his first podium with a third place at the Aragonese Grand Prix, then added a second place in Thailand. Those results contributed to a twelfth-place finish in the final championship standings. Despite losing the Rookie of the Year award to Ángel Piqueras, his debut campaign was widely considered a promising entry into the world series, particularly given the competitive depth of Moto3 in that period.
Lunetta continued with Sic58 Squadra Corse into the 2025 season, gaining a second year of Moto3 experience before his planned graduation to the intermediate class.
On 6 September 2025, Speed Up Racing announced that Lunetta would graduate to the Moto2 World Championship for the 2026 season, partnering Celestino Vietti under the SpeedRS Team banner. The move came after just two full seasons in Moto3, reflecting the confidence his performances had generated within the paddock.
Lunetta's career carries an additional layer of meaning through his sustained tribute to Marco Simoncelli. Riding number 58 throughout his junior career and then joining the Sic58 Squadra Corse team — founded in Simoncelli's memory — demonstrated a conscious continuity of purpose beyond results alone. His swift progression from junior champion to Moto3 podium finisher to Moto2 grid member before his twentieth birthday placed him among the faster-developing Italian riders of his generation.