d'ambrosio moved into single-seaters in 2003, and won the belgian formula renault (1.6 litre) championship. he also drove in the german-based formula könig championship in 2003. he moved into the french formula renault (2-litre) series for 2004. he finished fourth in the series and was top rookie. he switched to the italian formula renault championship in 2005, and finished fourth. in 2006, he drove in the formula renault 3.5 series, for tech 1 racing. he left the series after four rounds and zero points.