After an early career in karting, in which he became a national champion, Cantelli made his single-seater debut in 2006 in the Brazilian Formula Renault 2.0 series.

Driving for Dragão Motorsport and Cesário F.Renault, he took two podium places and three fastest laps to finish ninth in the standings.

At the end of the season, Cantelli took part in the four-race British Formula Renault 2.0 Winter Series, held at Brands Hatch and Croft.

[3] After missing the following event at Silverstone, Cantelli returned to the series at the Hungaroring, replacing Aleix Alcaraz at Italian team RC Motorsport.

Driving for Bassan Motorsport, he took three race victories and a further three podium places to finish as runner-up behind series champion Leonardo Cordeiro.