A Ponte Preta youth graduate, he was promoted to the main squad in 2006, but was third-choice (behind Jean and Aranha).
He made his first team debut on 24 February 2007, starting in a 1–2 away loss against Grêmio Barueri for the Campeonato Paulista championship.
Denis appeared regularly during that year's Série B, mainly profiting from Aranha's injury.
[1] He made his debut for the club three days later, replacing injured Rogério Ceni in a 2–0 away win against Portuguesa.
In the following year, after profiting from Ceni's serious injury, he appeared regularly for Tricolor, but was again backup after the latter's recovery.